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Oracle Database Real Application Testing User's Guide

1. 7 O T Set the section parameter to specify a particular section to generate in the report Possible values include SUMMARY default and ALL Comparing SQL Trials 6 11 Comparing SQL Trials Using APIs a Set the top_sql parameter to specify the number of SQL statements in a SQL tuning set to generate in the report By default the report shows the top 100 SQL statements impacted by the system change To generate an active report run the following script set trimspool on set trim on set pages 0 set long 1000000 set longchunksize 1000000 spool spa_active html SELECT DBMS_SQLPA REPORT_ANALYSIS_TASK task_name gt my_spa_task type gt active section gt all FROM dual spool off set linesize 1000 The following example illustrates a portion of a SQL script that you could use to create and display a comparison summary report in text format VAR rep CLOB EXEC rep DBMS_SQLPA REPORT_ANALYSIS_TASK my_spa_task text typical summary SET LONG 100000 LONGCHUNKSIZE 100000 LINESIZE 130 PRINT rep 3 Review the SQL Performance Analyzer report as described in Reviewing the SQL Performance Analyzer Report Using APIs on page 6 12 See Also Oracle Database PL SQL Packages and Types Reference for information about the DBMS_SQLPA EXECUTE_ANALYSIS_TASK and DBMS_SQLPA REPORT_ANALYSIS_TASK functions
2. The following example performs a test execute of the SQL statements remotely over a database link EXEC DBMS_SQLPA EXECUTE_ANALYSIS_TASK task_name gt my_spa_task execution_type gt TEST EXECUTE execution_name gt my_remote_trial_llg execution_params gt dbms_advisor arglist database_link LINK A B C BIZ COM Tuning Regressed SQL Statements After Testing a Database Upgrade In some cases SQL Performance Analyzer may identify SQL statements whose performance regressed after you upgrade the database on the test system You can tune the regressed SQL statements by using the SQL Tuning Advisor or SQL plan baselines as described in Chapter 6 Comparing SQL Trials This involves using APIs to build a subset of a SQL tuning set with only the regressed SQL statements transport this subset of regressed SQL statements to the remote database and running the SQL Tuning Advisor on the remote database Testing a Database Upgrade 7 15 Tuning Regressed SQL Statements After Testing a Database Upgrade Oracle Enterprise Manager does not provide support for fixing regressions after running SQL Performance Analyzer involving one or more remote SQL trials For more information see Tuning Regressed SQL Statements From a Remote SQL Trial Using APIs on page 6 24 If you are upgrading from Oracle Database 10g Release 2 and newer releases you can also create SQL plan baselines to instruct the optimizer to sele
3. Testing Database Upgrades from Oracle9i Database and Oracle Database 10g Release 1 Once the SQL tuning set is built you can use SQL Performance Analyzer to build a pre upgrade SQL trial from the execution plans and run time statistics in the SQL tuning set After the pre upgrade SQL trial is built you need to perform a test execute or generate plans of SQL statements in the SQL tuning set on the test system to build a post upgrade SQL trial SQL Performance Analyzer test executes the SQL statements using a public database link that you specify by connecting to the test system remotely and generating the execution plans and statistics for the SQL trial The database link should exist on the SQL Performance Analyzer system and connect to a remote user with privileges to execute the SQL tuning set on the test system You can run SQL Performance Analyzer to test a database upgrade from Oracle9i Database or Oracle Database 10g Release 1 using Oracle Enterprise Manager or APIs as described in the following sections Testing Database Upgrades from Oracle9i Database and Oracle Database 10g Release 1 Using Enterprise Manager a Testing Database Upgrades from Oracle9i Database and Oracle Database 10g Release 1 Using APIs Testing Database Upgrades from Oracle9i Database and Oracle Database 10g Release 1 Using Enterprise Manager To test a database upgrade from Oracle9i Database or Oracle Database 10 Release 1 using SQL Performance Analyzer
4. Testing a Database Upgrade 7 9 Upgrading from Oracle Database 10g Release 2 and Newer Releases plans and performance data at the source thereby resulting in a more accurate analysis The following example performs a test execute of the SQL statements remotely over a database link EXEC DBMS_SQLPA EXECUTE_ANALYSIS_TASK task_name gt my_spa_task execution_type gt TEST EXECUTE execution_name gt my_remote_trial_10g execution_params gt dbms_advisor arglist database_link LINK A B C BIZ COM Upgrading from Oracle Database 10g Release 2 and Newer Releases You can use SQL Performance Analyzer to test the impact on SQL response time of a database upgrade from Oracle Database 10g Release 2 or a newer release to any later release by capturing a SQL tuning set on the production system then executing it twice remotely over a database link on a test system first to create a pre change SQL trial then again to create a post change SQL trial The production system which you are upgrading from should be running Oracle Database 10g Release 2 or a newer release Initially the test system should also be running the same release To ensure that the analysis made by SQL Performance Analyzer is accurate the test system should contain an exact copy of the production data found on the production system Furthermore the hardware configuration should also be as similar to the production system as possible Nex
5. Select Generate Plans The SQL trial invokes the optimizer to create execution plans only without actually running the SQL statements In the Per SQL Time Limit list determine the time limit for SQL execution during the trial by performing one of the following actions a Select 5 minutes The execution will run each SQL statement in the SQL tuning set up to 5 minutes and gather performance data a Select Unlimited The execution will run each SQL statement in the SQL tuning set to completion and gather performance data Collecting execution statistics provides greater accuracy in the performance analysis but takes a longer time Using this setting is not recommended because the task may be stalled by one SQL statement for a prolonged time period a Select Customize and enter the specified number of seconds minutes or hours In the Comparison Metric list select the comparison metric to use for the comparison analysis Elapsed Time CPU Time User I O Time Buffer Gets Physical I O Optimizer Cost I O Interconnect Bytes Optimizer Cost is the only comparison metric available if you chose to generate execution plans only in the SQL trials To perform the comparison analysis by using more than one comparison metric perform separate comparison analyses by repeating this procedure with different metrics Ensure that pending optimizer statistics are collected and select Pending optimizer statistics col
6. amOrm Job Credentials Host Credentials Database Credentials Username limmchan d Username immchan Password eoeeee Password eeeeee Confirm Password eeceee Confirm Password eeeeee Save as Preferred Credential Connect As SYSDBA Save as Preferred Credential You need to login as SYSDBA or SYSOPER in order to restart the database 9 8 Oracle Database Real Application Testing User s Guide Capturing a Database Workload Using Enterprise Manager 6 Under Job Parameters define the parameters for the job a Inthe Job Name field enter a name for the job name or accept the system generated name a Inthe Description field enter an optional description of the job 7 Under Job Schedule specify a start time and duration for the workload capture Under Start select whether the job will run immediately by selecting Immediately or at a later time by selecting Later and specifying the desired time using the Date and Time fields Under Capture Duration specify how long the job will run by selecting Duration and specifying the desired duration using the Hours and Minutes fields To not specify a capture duration select Not Specified If a capture duration is unspecified the job must be stopped manually 8 Under Job Credentials enter the host and database login credentials a Under Host Credentials enter the username and password for the host system a Under Database Cr
7. 1 On the Software and Support page under Real Application Testing click SOL Performance Analyzer The SQL Performance Analyzer page appears 2 Under SQL Performance Analyzer Workflows click Upgrade from 9i or 10 1 7 6 Oracle Database Real Application Testing User s Guide Upgrading from Oracle9i Database and Oracle Database 10g Release 1 The Upgrade from 9i or 10 1 page appears Upgrade from 9i or 10 1 Task Information Pre upgrade Trial Post upgrade Trial Creation Method Execute SQLs Per SQL Time Limit Trial Comparison Comparison Metric Elapsed Time x Schedule Time Zone America Los_Angeles x Immediately O Later Task Name SQL Tuning Set Creation Method Build From SQL Tuning Set Database Link Create Database Link Description TIP Time limit is on elapsed time of test execution of SQL TIP Provide a PUBLIC database link connecting to a remote user with privileges to execute the Tuning Set SQL Date dun 3 2009 example Jun 3 2009 Time 6_M 43 00 M Oam OPM Under Task Information c In the Task Name field enter the name of the task In the SQL Tuning Set field enter the name of the SQL tuning set that was built Alternatively click the search icon to search for the SQL tuning set using the Search and Select SQL Tuning Set window The selected SQL tuning set now appears in the SQL Tunin
8. Alternatively you can run the Exadata simulation using the tcellsim sq 1 script 1 At the SQL prompt enter SORACLE_HOME rdbms admin tcellsim sql 2 Enter the name and owner of the SQL tuning set to use Enter value for sts_name MY_STS Enter value for sts_owner IMMCHAN The script then runs the following four steps automatically Creates a SQL Performance Analyzer task m Test executes SQL statements with Exadata simulation disabled a Test executes SOL statements with Exadata simulation enabled Compares performance and generates analysis report 3 14 Oracle Database Real Application Testing User s Guide 4 Creating a Pre Change SQL Trial After creating a SQL Performance Analyzer task and selecting a SQL tuning set as the input source you need to establish the initial environment on the test system Establishing the database environment on the test system involves manually making any necessary environmental changes that affect SQL optimization and performance These changes may include changing initialization parameters gathering or setting optimizer statistics and creating indexes It is recommended that you build a test system that is as similar to the production system as possible The dedicated workflows in Enterprise Manager simplifies this process by creating both SQL trials automatically and performing the change restricted to the testing session For information about setting up the database environment
9. 15 Review the options and parameters that have been defined for the workload replay Before starting replay reset the system clock to a value that is as close to the capture start time as possible This minimizes any replay divergence that may result from replaying a time sensitive workload For more information see Resetting the System Time on page 11 2 To begin replay click Submit If no replay clients are connected this button will be disabled To make changes click Back To cancel replay without saving changes click Cancel Once the replay is started the View Workload Replay page appears For information about monitoring an active workload replay see Monitoring an Active Workload Replay on page 11 13 11 12 Oracle Database Real Application Testing User s Guide Monitoring Workload Replay Using Enterprise Manager Monitoring Workload Replay Using Enterprise Manager This section describes how to monitor workload replay using Enterprise Manager The primary tool for monitoring workload replay is Oracle Enterprise Manager Using Enterprise Manager you can Monitor or stop an active workload replay View a completed workload replay If for some reason Oracle Enterprise Manager is unavailable you can monitor workload replay using APIs and views as described in Monitoring Workload Replay Using APIs on page 11 26 This section contains the following topics Monitoring an Active Workload Replay Viewing a Complet
10. In this example the GET_CAPTURE_INFO procedure retrieves all information regarding the workload capture in the dec06 directory and returns the appropriate cap_id for the workload capture The REPORT function generates a text report using the cap_id that was returned by the GET_CAPTURE_INFO procedure The GET_CAPTURE_INFO procedure uses the dir required parameter which specifies the name of the workload capture directory object The REPORT function uses the following parameters a The capture_id required parameter relates to the directory that contains the workload capture for which the report will be generated The directory should be a valid directory in the host system containing the workload capture The value of this parameter should match the cap_id returned by the GET_CAPTURE_INFO procedure a The format parameter required parameter specifies the report format Valid values include DBMS_WORKLOAD_CAPTURE TYPE_TEXT and DBMS_ WORKLOAD_REPLAY TYPE_HTML For information about how to interpret the workload capture report see Reviewing Workload Capture Reports on page 12 3 12 2 Oracle Database Real Application Testing User s Guide Using Workload Replay Reports See Also a Oracle Database PL SQL Packages and Types Reference for information about the DBMS_WORKLOAD_CAPTURE package Reviewing Workload Capture Reports The workload capture report contains various types of in
11. This section describes how to generate a SQL Performance Analyzer report using the DBMS_WORKLOAD_REPLAY package The SQL Performance Analyzer report can be used to compare a SQL tuning set from a workload capture to another SQL tuning set from a workload replay or two SQL tuning sets from two workload replays Comparing SQL tuning sets with Database Replay provides more information than SQL Performance Analyzer test execute because it considers and shows all execution plans for each SQL statement while SQL 12 8 Oracle Database Real Application Testing User s Guide Using Compare Period Reports Performance Analyzer test execute generates only one execution plan per SQL statement for each SQL trial To generate a replay compare period report use the DBMS_WORKLOAD REPLAY COMPARE_SQLSET_REPORT procedure BEGIN DBMS_WORKLOAD_REPLAY COMPARE_SQLSET REPORT replay_idl gt 12 format gt DBMS WORKLOAD CAPTURE TYPE_HTML result gt report_bind END In this example the COMPARE_SQLSET_REPORT procedure generates a SQL Performance Analyzer report in HTML format that compares a SQL tuning set captured during the workload replay with a replay ID of 12 to a SQL tuning set captured during workload capture The COMPARE_SQLSET_REPORT procedure in this example uses the following parameters a The replay_id1 parameter specifies the numerical identifier of the wo
12. gt wrc mode list_hosts replaydir replay In this example the wrc executable is executed to list all hosts that participated in capturing or replaying the workload capture stored in a subdirectory named replay under the current directory In the following sample output the hosts that participated in the workload capture and three subsequent replays are shown Workload Replay Client Release 11 2 0 0 2 Production on Fri May 1 13 44 48 2009 Copyright c 1982 2009 Oracle All rights reserved Hosts found Capture prod1 prod2 Replay 1 test1 Replay 2 test1 test2 Replay 3 Replaying a Database Workload 11 7 Replaying a Database Workload Using Enterprise Manager testwin Replaying a Database Workload Using Enterprise Manager This section describes how to replay a database workload using Enterprise Manager The primary tool for replaying database workloads is Oracle Enterprise Manager If for some reason Oracle Enterprise Manager is unavailable you can also replay database workloads using APIs as described in Replaying a Database Workload Using APIs on page 11 18 To replay a database workload using Enterprise Manager 1 On the Software and Support page under Real Application Testing click Database Replay The Database Replay page appears 2 Inthe Go to Task column click the icon that corresponds to the Replay Workload task The Replay Workload page appears Replay Workload The captured wor
13. replay_connection gt dlsun244 3434 bjava21 END In this example the connection that corresponds to the connection ID 101 will use the new connection string defined by the replay_connection parameter Replaying a Database Workload 11 19 Replaying a Database Workload Using APIs The REMAP_CONNECTION procedure in this example uses the following parameters a The connection_id required parameter is generated when initializing replay data and corresponds to a connection from the workload capture a The replay_connection optional parameter specifies the new connection string that will be used during workload replay Setting Workload Replay Options After the replay data is initialized and the connections are appropriately remapped you need to prepare the database for workload replay For information about workload replay preparation see Steps for Replaying a Database Workload on page 11 2 To prepare workload replay on the replay system use the PREPARE_REPLAY procedure BEGIN DBMS_WORKLOAD_REPLAY PREPARE REPLAY synchronization gt TRUE capture_sts gt TRUE sts_cap_interval gt 300 END In this example the PREPARE_REPLAY procedure prepares a replay that has been previously initialized The COMMIT order in the workload capture will be preserved A SQL tuning set will also be captured in parallel with the workload replay The PREPARE_REPLAY procedure uses
14. 3 12 Oracle Database Real Application Testing User s Guide Creating an Analysis Task Using APIs The Create SQL Performance Analyzer Task page appears Create SQL Performance Analyzer Task The SQL Performance Analyzer Task is a container for the execution of trial experiments designed to test the effects of changes in execution environment on the SQL performance of an STS Name Owner IMMCHAN Description TIP Use the description to characterize the intended SQL Performance Analyzer investigations SQL Tuning Set The SQL Tuning Set is the basis for SQL Performance Analyzer Task experiments The STS should represent a coherent set of SQL for the changes being investigated e g full workload for an upgrade test E Name A TIP You can create a new STS here Link to STS Creation Wizard Cancel Create 3 Inthe Name field enter the name of the task 4 Inthe Description field optionally enter a description of the task 5 Under SQL Tuning Set in the Name field enter the name the SQL tuning set that contains the SQL workload to be analyzed Alternatively click the search icon to select a SQL tuning set from the Search and Select SQL Tuning Set window 6 Click Create The Guided Workflow page appears The Status icon of this step has changed to a check mark and the Execute icon for the next step is now enabled 7 Once the analysis task is created you can build the pre change pe
15. For information about how to interpret the SQL Performance Analyzer report see Reviewing the SQL Performance Analyzer Report Using Oracle Enterprise Manager on page 6 3 The Report window opens while the report is being generated Once the report is generated you can save the report by clicking Save to File Generating Compare Period Reports Using APIs This section describes how to generate compare period reports using the DBMS_ WORKLOAD_REPLAY package You can also use Oracle Enterprise Manager to generate compare period reports as described in Generating Compare Period Reports Using Enterprise Manager on page 12 6 This section contains the following topics a Generating Replay Compare Period Reports Using APIs Analyzing Replayed Workload 12 7 Using Compare Period Reports Generating SQL Performance Analyzer Reports Using APIs Generating Replay Compare Period Reports Using APIs This section describes how to generate a replay compare period report using the DBMS_WORKLOAD_REPLAY package Use the replay compare period report to perform a high level comparison of one workload replay to its capture or to another replay of the same capture Only workload replays that contain at least 5 minutes of database time can be compared using this report To generate a replay compare period report use the DBMS_WORKLOAD REPLAY COMPARE_PERTOD_REPORT procedure BEGIN DBMS_WORKLOAD
16. Reviewing the SQL Performance Analyzer Report General Information The General Information section contains basic information and metadata about the workload comparison performed by SQL Performance Analyzer To review general information 1 On the SQL Performance Analyzer Task Report page review the summary at the top of the page SQL Tuning Set Name STS CURSOR CACHE SQL Trial 1 SQL_TRIAL_1241213421833 STS Owner IMMCHAN SQL Trial 2 SQL_TRIAL_1241213881923 Total SQL Statements 1 134 Comparison Metric Elapsed Time SQL Statements With 331 SQL Statements With rors Timeout SQL Statements 15 Unsupported This summary includes the following information a The name and owner of the SQL tuning set The total number of SQL statements in the tuning set and the number of SQL statements that had errors are unsupported or timed out a The names of the SQL trials and the comparison metric used 2 Optionally click the link next to SQL Tuning Set Name The SQL Tuning Set page appears This page contains information such as SQL ID and SQL text about every SQL statement in the SQL tuning set 3 Click the link next to SQL Statements With Errors if errors were found The Errors table reports all errors that occurred while executing a given SQL workload An error may be reported at the SQL tuning set level if it is common to all SQL executions in the SQL tuning set or at the execution level if it is specific to a SQL statement or
17. The information generated by SQL Trace is stored in SQL trace files SQL Performance Analyzer consumes the following information from these files SQL text and username under which parse occurred Bind values for each execution CPU and elapsed times Physical reads and logical reads Number of rows processed Execution plan for each SQL statement only captured if the cursor for the SQL statement is closed Although it is possible to enable SQL Trace for an instance it is recommended that you enable SQL Trace for a subset of sessions instead When the SQL Trace facility is enabled for an instance performance statistics for all SOL statements executed in the instance are stored into SQL trace files Using SQL Trace in this way can have a severe performance impact and may result in increased system overhead excessive CPU Testing a Database Upgrade 7 3 Upgrading from Oracle9i Database and Oracle Database 10g Release 1 usage and inadequate disk space It is required that trace level be set to 4 to capture bind values along with the execution plans For production systems running Oracle Database 10g Release 1 use the DBMS_ MONITOR SESSION_TRACE_ENABLE procedure to enable SQL Trace transparently in another session You should also enable binds explicitly by setting the binds procedure parameter to TRUE its default value is FALSE After enabling SQL Trace identify the SQL trace files cont
18. To generate and review the SQL Performance Analyzer report 1 On the Software and Support page under Real Application Testing click SQL Performance Analyzer The SQL Performance Analyzer page appears A list of existing SQL Performance Analyzer tasks are displayed Under SQL Performance Analyzer Tasks select the task for which you want to view a SQL Performance Analyzer report and click View Latest Report The SQL Performance Analyzer Task Report page appears Review the general information about the performance analysis as described in Reviewing the SQL Performance Analyzer Report General Information on page 6 5 Review general statistics as described in Reviewing the SQL Performance Analyzer Report Global Statistics on page 6 5 Optionally review the detailed statistics as described in Reviewing the SQL Performance Analyzer Report Global Statistics Details on page 6 7 To generate an active report click Save to generate and save the report or Mail to generate and mail the report as an HTML attachment Active reports include information about the top SQL statements from each category such as improved regressed and changed plans with pre change and post change statistics explain plans and task summary 6 4 Oracle Database Real Application Testing User s Guide Comparing SQL Trials Using Oracle Enterprise Manager For more information see About SQL Performance Analyzer Active Reports on page 6 7
19. a Oracle Database Utilities for information about using Data Pump Capturing a Database Workload 9 1 Workload Capture Options Workload Capture Options Proper planning before workload capture is required to ensure that the capture will be accurate and useful when replayed in another environment Before capturing a database workload carefully consider the following options a Restarting the Database Using Filters with Workload Capture Setting Up the Capture Directory Restarting the Database While this step is not required Oracle recommends that the database be restarted before capturing the workload to ensure that ongoing and dependent transactions are allowed to be completed or rolled back before the capture begins If the database is not restarted before the capture begins transactions that are in progress or have yet to be committed will not be fully captured in the workload Ongoing transactions will thus not be replayed properly because only the part of the transaction whose calls were captured will be replayed This may result in undesired replay divergence when the workload is replayed Any subsequent transactions with dependencies on the incomplete transactions may also generate errors during replay On a busy system it is normal to see some replay divergence but the replay can still be used to perform meaningful analysis of a system change if the diverged calls do not make up a significant portion of the replay in ter
20. capture files 8 2 capturing 8 2 9 5 9 13 9 14 exporting data 9 16 managing 9 12 monitoring 9 10 9 16 options 9 2 prerequisites 9 1 reporting 12 1 restarting the database 9 2 restrictions 9 3 stopping 9 11 9 15 workload filters about 9 3 11 4 defining 9 14 exclusion filters 9 3 11 4 inclusion filters 9 3 11 4 workload preprocessing about 8 3 10 1 preprocessing 10 1 10 4 workload replay about 8 3 11 1 cancelling 11 25 exporting data 11 25 filters 11 21 monitoring 11 13 11 26 options 11 3 11 20 pausing 11 25 replaying 11 8 11 18 Index reporting 12 3 resuming 11 25 starting 11 24 steps 11 2 database upgrades testing 7 1 database version production system 7 2 7 10 system running SQL Performance Analyzer 7 2 7 10 test system 7 2 7 10 DBMS_SPM package LOAD_PLANS_FROM_SQLSET function 6 26 DBMS_SQLPA package CREATE_ANALYSIS_TASK function 3 13 EXECUTE_ANALYSIS_TASK procedure 4 4 5 3 6 10 7 9 7 14 REPORT_ANALYSIS_TASK function 6 11 SET_ANALYSIS_TASK PARAMETER procedure 3 14 DBMS_SQLTUNE package CREATE_TUNING_TASK function 6 23 SELECT_SQL_TRACE function 7 5 DBMS_WORKLOAD_CAPTURE package ADD_FILTER procedure 9 14 DELETE_FILTER procedure 9 14 EXPORT_AWR procedure 9 16 FINISH_CAPTURE procedure 9 15 GET_CAPTURE_INFO procedure 12 2 REPORT function 12 2 START_CAPTURE procedure 9 15 DBMS_WORKLOAD_REPLAY package ADD FILTER procedure 11 21 CANCEL_REPLAY procedur
21. execution_type gt TEST EXECUTE execution_name gt my_exec_AFTER_change Once the post change performance data is built you can compare the pre change SQL trial to the post change SQL trial by running a comparison analysis as described in Chapter 6 Comparing SQL Trials See Also a Oracle Database PL SQL Packages and Types Reference to learn about the DBMS_SQLPA EXECUTE_ANALYSIS_TASK function 5 4 Oracle Database Real Application Testing User s Guide 6 Comparing SQL Trials After the post change SQL performance data is built you can compare the performance data collected in the pre change SQL trial to the post change SQL trial by running a comparison analysis using SQL Performance Analyzer After the comparison analysis is completed you can generate a report to identify the SQL statements that have improved remained unchanged or regressed due to the system change The SQL Performance Analyzer report calculates two chief impact measurements for the change in performance of each SQL statement Impact on workload This represents the percentage of impact that this change to the SQL statement has on the cumulative execution time of the workload after accounting for execution frequency For example a change that causes a SQL statement s cumulative execution time to improve from 101 seconds to 1 second where the rest of the workload had a total execution time of 99 seconds before the change
22. see Setting Up the Test System on page 2 4 Note You can optionally run SQL trials on a remote system by providing access to a public database link When conducting remote SQL trials the database version of the remote database where the SQL statements are executed must be less than or equal to the database version of the database to which it connects Starting with Oracle Database release 11 2 0 2 the remote database can be a read only database such as an Oracle Active Data Guard instance Once the environment on the test system is properly configured you can build the pre change version of performance data before performing the system change You can build SQL trials using SQL Performance Analyzer by using one of the following methods a Executing the SQL statements in the workload Generating execution plans for the SQL statements in the workload a Loading performance data and execution plans from a SQL tuning set APIs only For more information see Measuring the Pre Change SQL Performance on page 2 5 This chapter described how to create the pre change SQL trial and contains the following topics a Creating a Pre Change SQL Trial Using Enterprise Manager a Creating a Pre Change SQL Trial Using APIs Creating a Pre Change SQL Trial 4 1 Creating a Pre Change SQL Trial Using Enterprise Manager Note The primary interface for creating a pre change SQL trial is Oracle Enterprise Manager If for some re
23. the workload capture begins automatically Click Refresh Capturing a Database Workload 9 9 Monitoring Workload Capture Using Enterprise Manager The View Workload Capture page appears If the job is scheduled to start immediately but the database will not be restarted the workload capture begins automatically and the View Workload Capture page appears a If the job is scheduled to start at a later time the Database Replay page appears with a confirmation that the job has been successfully created Once workload capture begins you can monitor the capture process using the View Workload Capture page as described in Monitoring Workload Capture Using Enterprise Manager on page 9 10 Tip After capturing a workload on the production system you need to preprocess the captured workload as described in Chapter 10 Preprocessing a Database Workload Monitoring Workload Capture Using Enterprise Manager This section describes how to monitor workload capture using Enterprise Manager The primary tool for monitoring workload capture is Oracle Enterprise Manager Using Enterprise Manager you can a Monitor or stop an active workload capture a View or delete a completed workload capture If for some reason Oracle Enterprise Manager is unavailable you can monitor workload capture using views as described in Monitoring Workload Capture Using Views on page 9 16 This section contains the following topics a Monitoring an A
24. use the INITIALIZE_REPLAY procedure BEGIN DBMS_WORKLOAD_REPLAY INITIALIZE_REPLAY replay_name gt dec06_102 replay_dir gt dec06 END In this example the INITIALIZE_REPLAY procedure loads preprocessed workload data from the dec06 directory into the database The INITIALIZE_REPLAY procedure in this example uses the following parameters The replay_name required parameter specifies a replay name that can be used with other APIs to retrieve settings and filters of previous replays The replay_dir required parameter specifies the directory that contains the workload capture that will be replayed See Also Preprocessing a Database Workload Using APIs on page 10 4 for information about preprocessing a workload capture a Setting Up the Test System on page 11 1 for information preparing the test system Connection Remapping After the replay data is initialized connection strings used in the workload capture need to be remapped so that user sessions can connect to the appropriate databases and perform external interactions as captured during replay To view connection mappings use the DBA_WORKLOAD_CONNECTION_MAP view For information about connection remapping see Remapping Connections on page 11 3 To remap connections use the REMAP_CONNECTION procedure BEGIN DBMS_WORKLOAD_REPLAY REMAP CONNECTION connection_id gt 101
25. user with privileges to execute the Tuning Set SQL Post upgrade Trial Use the same system as in the pre upgrade trial Database Link Create Database Lin TIP Same creation method and per SQL time limit as in the pre upgrade trial will be applied Trial Comparison Comparison Metric Elapsed Time v Schedule Time Zone America Los_Angeles Immediately O Later Date Yun 3 2009 example Jun 3 2009 Time 8 29 00 M am OPM 3 Under Task Information a Inthe Task Name field enter the name of the task b Inthe SQL Tuning Set field enter the name of the SQL tuning set that was built Alternatively click the search icon to search for the SQL tuning set using the Search and Select SQL Tuning Set window The selected SQL tuning set now appears in the SQL Tuning Set field c Inthe Description field optionally enter a description of the task In the Creation Method field select a Execute SQLs to generate both execution plans and statistics for each SQL statement in the SQL tuning set by actually running the SQL statements remotely on the test system over a public database link 7 12 Oracle Database Real Application Testing User s Guide Upgrading from Oracle Database 10g Release 2 and Newer Releases a Generate Plans to create execution plans remotely on the test system over a public database link without actually runnin
26. would have a 50 2x value for this measurement Impact on SQL This represents the percentage of impact that this change to the SQL statement has on the SQL statement s response time For example a change that causes a SQL statement s response time to improve from 10 seconds to 1 second will have a 90 10x value for this measurement For more information see Comparing Performance Measurements on page 2 7 This chapter describes how to compare and analyze the performance data from the pre change and post change SQL trials and contains the following topics Comparing SQL Trials Using Oracle Enterprise Manager Comparing SQL Trials Using APIs Note The primary interface for comparing SQL trials is Oracle Enterprise Manager If for some reason Oracle Enterprise Manager is unavailable you can compare SQL trials using the DBMS_SQLPA PL SQL package Tip Before comparing SQL trials you need to create a post change SQL trial as described in Chapter 5 Creating a Post Change SQL Trial Comparing SQL Trials 6 1 Comparing SQL Trials Using Oracle Enterprise Manager Comparing SQL Trials Using Oracle Enterprise Manager Comparing SQL trials using Oracle Enterprise Manager involves the following steps a Analyzing SQL Performance Using Oracle Enterprise Manager a Reviewing the SQL Performance Analyzer Report Using Oracle Enterprise Manager a Tuning Regressed SQL Statements Using Oracle Enterprise Manage
27. Analyzer task If unspecified this parameter will default to the current user SPA_COMPARE_EXEC Execution name of the compare performance trial for the specified SQL Performance Analyzer task If unspecified this parameter defaults to the most recent execution of the COMPARE PERFORMANCE type for the given SQL Performance Analyzer task After tuning the regressed SQL statements you should test these changes using SQL Performance Analyzer Run anew SQL trial on the test system followed by a second comparison between this new SQL trial and the first SQL trial to validate your Comparing SQL Trials 6 23 Comparing SQL Trials Using APIs results Once SOL Performance Analyzer shows that performance has stabilized implement the fixes from this step to your production system Starting with Oracle Database 11g Release 2 SQL Tuning Advisor performs an alternative plan analysis when tuning a SQL statement SQL Tuning Advisor reviews the execution history of the SQL statement including any historical plans stored in the Automatic Workload Repository If SQL Tuning Advisor finds alternate plans it allows you to choose a specific plan and create a plan baseline to ensure that the desired execution plan is used for that SQL statement See Also a Oracle Database Performance Tuning Guide for information about using the SQL Tuning Advisor Oracle Database Performance Tuning Guide for information about alternative plan analys
28. Analyzing Replayed Workload 12 1 Using Workload Capture Reports The Database Replay page appears 2 Click View Workload Capture History The View Workload Capture History page appears 3 Select the workload capture for which you want to run a workload capture report and click View The View Workload Capture page appears 4 To view the workload capture report click View Workload Capture Report The Report window opens while the report is being generated 5 Once the report is generated you can save the report by clicking Save to File For information about how to interpret the workload capture report see Reviewing Workload Capture Reports on page 12 3 Generating Workload Capture Reports Using APIs This section describes how to generate a workload capture report using the DBMS_ WORKLOAD_CAPTURE package You can also use Oracle Enterprise Manager to generate a workload capture report as described in Generating Workload Capture Reports Using Enterprise Manager on page 12 1 To generate a report on the latest workload capture use the DBMS_WORKLOAD_ CAPTURE GET_CAPTURE_INFO procedure and the DBMS_WORKLOAD_ CAPTURE REPORT function DECLARE cap_id NUMBER cap_rpt CLOB BEGIN cap_id DBMS_WORKLOAD_CAPTURE GET_CAPTURE_INFO dir gt dec06 cap_rpt DBMS WORKLOAD _CAPTURE REPORT capture_id gt cap_id format gt DBMS WORKLOAD _CAPTURE TYPE_TEXT END
29. DML or SQL queries A comparison of several statistics such as database time average active sessions and user calls between the workload capture and the workload replay is also provided Introduction to Database Replay 8 3 Analysis and Reporting The replay compare period report can be used to perform a high level comparison of one workload replay to its capture or to another replay of the same capture A divergence summary with an analysis of whether any data divergence occurred and if there were any significant performance changes is also provided Furthermore Automatic Database Diagnostic Monitor ADDM findings are incorporated into these reports For advanced analysis Automatic Workload Repository AWR reports are available to enable detailed comparison of performance statistics between the workload capture and the workload replay The information available in these reports is very detailed and some differences between the workload capture and replay can be expected The SQL Performance Analyzer report can be used to compare a SQL tuning set from a workload capture to another SQL tuning set from a workload replay or two SQL tuning sets from two workload replays Comparing SQL tuning sets with Database Replay provides more information than SQL Performance Analyzer test execute because it considers and shows all execution plans for each SQL statement while SQL Performance Analyzer test execute generates only one execution plan p
30. Description Created SQL Executed Status INITIAL_SQL_TRIAL parameter optimizer_use_pending_statistics set to FALSE 7 26 10 5 37 PM Yes COMPLETED SECOND_SQL_TRIAL parameter optimizer_use_pending_statistics set to TRUE 7 26 10 5 38 PM Yes COMPLETED Y SQL Trial Comparisons Compare SQL Trials to assess change impact of environmental differences on SQL Tuning Set execution costs Run SQL Trial Comparison Compare Comparison SQL Tune Trial 1 Name Trial 2 Name Metric Created Status Report Report INITIAL_SQL_TRIAL SECOND_SQL_TRIAL Optimizer Cost 7 26 10 5 38 COMPLETED pe PM This page contains the following sections a SQL Tuning Set This section summarizes information about the SQL tuning set including its name owner description and the number of SQL statements it contains a SQL Trials This section includes a table that lists the SQL trials used in the SQL Performance Analyzer task SQL Trial Comparisons This section contains a table that lists the results of the SQL trial comparisons 12 Click the icon in the Comparison Report column The SQL Performance Analyzer Task Result page appears 3 8 Oracle Database Real Application Testing User s Guide Creating an Analysis Task Using Enterprise Manager 13 Review the results of the performance analysis as described in Reviewing the SQL Performance Analyzer Report Using Oracle Enterprise Manager on page 6 3 Any regressions found in performance can be fixed using SQL
31. Enterprise Manager This section describes how to generate a workload replay report using Oracle Enterprise Manager The primary tool for generating workload replay reports is Oracle Enterprise Manager If for some reason Oracle Enterprise Manager is unavailable you can generate workload replay reports using APIs as described in Generating Workload Replay Reports Using APIs on page 12 4 To generate a workload replay report using Enterprise Manager 1 On the Software and Support page under Real Application Testing click Database Replay Analyzing Replayed Workload 12 3 Using Workload Replay Reports The Database Replay page appears 2 Inthe Go to Task column click the icon that corresponds to the Replay Workload task The Replay Workload page appears 3 In the Directory Object list select a directory that contains the preprocessed workload that was used for the replay for which you want to generate a workload replay report After a directory is selected the Replay Workload page will be refreshed to display the Capture Summary and the Replay History sections 4 Under Replay History select the replay for which you want to generate a workload replay report and click View The View Workload Replay page appears 5 Click View Workload Replay Report Replay History view Export AWR Data AWR Data Select Name Exported REPLAY x112 Completed 00 02 06 Jun 4 2009 3 56 32 AM Jun 4 2009 3 5
32. Name my_exec_AFTER_change Execution Type TEST EXECUTE Execution Type TEST EXECUTE Description Description Scope COMPREHENSIVE Scope COMPREHENSIVE Status COMPLETED Status COMPLETED Started 05 21 2007 11 22 06 Started 05 21 2007 11 25 56 Last Updated 05 21 2007 11 24 01 Last Updated 05 21 2007 11 28 30 Global Time Limit 1800 Global Time Limit 1800 Per SQL Time Limit UNUSED Per SQL Time Limit UNUSED Number of Errors Han Number of Errors 0 In Example 6 1 the Task Information section indicates that the task name is my_spa_ task The Workload Information section indicates that the task compares executions of the my_sts SQL tuning set which contains 101 SQL statements As shown in the Execution Information section the comparison execution is named my_exec_ compare The Analysis Information sections shows that SQL Performance Analyzer compares two executions of the my_sts SQL tuning set my_exec_BEFORE_change and my_ exec_AFTER_change using buffer_gets as a comparison metric Result Summary The Result Summary section summarizes the results of the SQL Performance Analyzer task The Result Summary section is divided into the following subsections a Overall Performance Statistics a Performance Statistics of SOL Statements a Errors Overall Performance Statistics The Overall Performance Statistics subsection displays statistics about the overall performance of the entire SQL workload This section is a
33. Name STS_CURSOR_CACHE SQL Trial 1 SQL_TRIAL_1280193369674 STS Owner IMMCHAN SQL Trial 2 SQL_TRIAL_1280193481612 Total SQL Statements 1 584 Comparison Metric Elapsed Time SQL Statements With SQL Statements With E 128 i rrors Timeout SQL Statements 141 Unsupported Global Statistics Projected Workload Elapsed Time SQL Statement Count Recommendations SQL Tune Report 10 0 g 2 000 IMMCHAN_TUNE O TS H m 5 0 g 1 000 a 25 Bo a 0 0 Improved Regressed Unchanged r eae Change in Elapsed Time F E SQLTriai1 SQL Trial 2 m New Plan M Same Plan Improvement Impact 2 i i Regression Impact 4 4 Overall Impact 2 Top 10 SQL Statements Based on Impact on Workload Elapsed Time sec SQL ID Net Impact on Workload SQL Trial 1 SQL Trial 2 Net Impact on SQL New Plan dagfku2m205ry 1 910 0 000 0 000 41 820 N Y ab ktcdksu27 1 620 0 542 0 660 21 770 N Y cp5caasd2udnw 1 310 0 037 0 041 13 050 N Y 53saa2zkr6wc3 1 140 0 000 0 000 131 710 N YD Sww6hx92ymmm 0 380 0 000 0 000 164 000 N T djtsv9x4jwtrt 0 340 0 001 0 000 38 220 N t d972cwyzapk6a 0 320 0 065 0 042 35 750 N Y cst19hcznakat 0 300 0 000 0 000 53 850 N T db78fxqxwxt7r 0 290 0 000 0 000 33 870 N Bac2h3qfahnxw 0 280 0 000 0 000 34 370 N Tip Before you can view the SQL Performance Analyzer report compare the pre change version of performance data with the post change version as described in Comparing SQL Trials Using Oracle Enterprise Manager on page 6 2
34. Number of Calls column to bring up the Diverged Replaying a Database Workload 11 15 Monitoring Workload Replay Using Enterprise Manager Calls During Replay page The Diverged Calls During Replay page shows the most relevant set of replayed calls that diverged from the workload captured by grouping them based on common attribute values and specified filter conditions To view details about a particular diverged call such as the call attributes SQL text and bind variables click the corresponding link in the SQL ID column to bring up the Replay Diverged Statement page To view a detailed comparison of the workload during capture and replay expand Detailed Comparison Y Detailed Comparison Capture Replay Percentage of Capture Duration hh mm ss 00 05 53 00 02 06 ME 35 69 Database Time hh mm ss 00 00 01 00 00 12 _ 200 00 Average Active Sessions 0 00 0 02 n a User Calls 189 139 i 100 00 The Detailed Comparison section displays the following information a Duration The duration that was captured in a workload is compared to the amount of time it took to replay the workload In the Capture column the duration of the time period that was captured is shown In the Replay column the amount of time it took to replay the workload is shown The Percentage of Capture column shows the percentage of the captured duration that it took to replay the workload If the value is under 100 percent the replay system processed the wor
35. Oracle Database Real Application Testing User s Guide Measuring the Pre Change SQL Performance To run SQL Performance Analyzer you must first create a SQL Performance Analyzer task A task is a container that encapsulates all of the data about a complete SQL Performance Analyzer analysis A SQL Performance Analyzer analysis comprises of at least two SQL trials and a comparison A SQL trial encapsulates the execution performance of a SQL tuning set under specific environmental conditions When creating a SOL Performance Analyzer task you will need to select a SQL tuning set as its input source When building SQL trials using the test execute or explain plan methods the SQL tuning set will be used as the source for SQL statements The SQL Performance Analyzer analysis will show the impact of the environmental differences between the two trials See Also a Chapter 3 Creating an Analysis Task for information about how to create a SQL Performance Analyzer task Measuring the Pre Change SQL Performance Create a pre change SQL trial before making the system change You can use the following methods to generate the performance data needed for a SQL trial with SQL Performance Analyzer a Test execute This method test executes SQL statements through SQL Performance Analyzer This can be done on the database running SPA Performance Analyzer or on a remote database a Explain plan This method generates execution plans only for SQL st
36. Replay Options asosii iesise eieiei e e i irii AR A a i E 11 3 Using Filters with Workload Replay ccceesscsssssssssssesssesesescsessesesescsesssesesescsssssesescssenssesessees 11 4 Setting Up Replay Clients ici s sctscctsciiestitiacsgiehesacsteielansiisdepledesstastaasebil REE aa east 11 5 Replaying a Database Workload Using Enterprise Manager cccccece esses eeseeeeees 11 8 Monitoring Workload Replay Using Enterprise Managet 0 ccccccccsse ee eeeeeeeteeeeeees 11 13 Monitoring an Active Workload Replay cccccsssssssssssssesesescsssssesescsesesesescscsssesesescsessesseesses 11 13 Viewing a Completed Workload Replay cece cesses sseseseesesesessssessesssssssssesesesesesees 11 14 Replaying a Database Workload Using APIs 0 0 cccccsessssssssssseesesesesstesesesescsesesesescseseseseseseses 11 18 Initializing Replay Dataiss cc cccnnts anced hes Mo dade alee ae das eats 11 19 Connection Remap ping ssena eaa a A a To aa aaao aaa n iiaei aieiaa hiet 11 19 Setting Workload Replay Options s sssssssssssississessestiesisstsssessestesessennsestentesenneesiestenensnesteseenet 11 20 Defining Workload Replay Filters and Replay Filter Sets 0 cccceesseseeesssssesesesenenssesesens 11 21 Setting the Replay Timeout ACtiON ssssssssssssississessesrirsisstssseniesiesesstnntesieniesenntesienreneeseesnestente 11 23 Starting a Workload Replaysnssssi nanninannan n a a Ea 11 24 Pausi ng a Workload Replay icssi
37. Reports replay attempts from this directory The procedure first imports a row into DBA_ WORKLOAD_CAPTURES which contains information about the workload capture It then imports a row for every replay attempt retrieved from the replay directory into the DBA_WORKLOAD_REPLAYS view The SELECT statement returns the appropriate rep_id for the latest replay of the workload The REPORT function generates a text report using the rep_id that was returned by the SELECT statement The GET_CAPTURE_INFO procedure uses the dir required parameter which specifies the name of the workload replay directory object The REPORT function uses the following parameters a The replay_id required parameter relates to the directory that contains the workload replay for which the report will be generated The directory should be a valid directory in the host system containing the workload replay The value of this parameter should match the rep_id returned by the GET_CAPTURE_INFO procedure a The format parameter required parameter specifies the report format Valid values include DBMS_WORKLOAD_REPLAY TYPE_TEXT DBMS _ WORKLOAD_REPLAY TYPE_HTML and DBMS_WORKLOAD_REPLAY TYPE_ XML For information about how to interpret the workload replay report see Reviewing Workload Replay Reports on page 12 5 See Also a Oracle Database PL SQL Packages and Types Reference for information about the DBMS_WORKLOAD_RE
38. Resuming a Workload Replay To resume a workload replay that is paused use the RESUME_REPLAY procedure BEGIN DBMS_WORKLOAD_REPLAY RESUME_REPLAY END Cancelling a Workload Replay To cancel a workload replay use the CANCEL_REPLAY procedure BEGIN DBMS_WORKLOAD_REPLAY CANCEL_REPLAY END Exporting AWR Data for Workload Replay Exporting AWR data enables detailed analysis of the workload This data is also required if you plan to run the AWR Compare Period report on a pair of workload captures or replays To export AWR data use the EXPORT_AWR procedure BEGIN DBMS_WORKLOAD_REPLAY EXPORT_AWR replay_id gt 1 END Replaying a Database Workload 11 25 Monitoring Workload Replay Using APIs In this example the AWR snapshots that correspond to the workload replay with a replay ID of 1 are exported along with any SQL tuning set that may have been captured during workload replay The EXPORT_AWR procedure uses the replay_id required parameter which specifies the ID of the replay whose AWR snapshots will be exported This procedure will work only if the corresponding workload replay was performed in the current database and the AWR snapshots that correspond to the original replay time period are still available Monitoring Workload Replay Using APIs This section describes how to monitor workload replay using APIs and views You can also use Oracle Enterprise Manager to
39. Reviewing the SQL Performance Analyzer Report Using APIs The SQL Performance Analyzer report is divided into the following sections a General Information a Result Summary a Result Details This section uses a sample report to illustrate how to review the SQL Performance Analyzer report The sample report uses buf fer_gets as the comparison metric to compare the pre change and post change executions of a SQL workload General Information The General Information section contains basic information and metadata about the SQL Performance Analyzer task the SQL tuning set used and the pre change and post change executions Example 6 1 shows the General Information section of a sample report Example 6 1 General Information Task Information Workload Information 6 12 Oracle Database Real Application Testing User s Guide Comparing SQL Trials Using APIs Task Name my_spa_task SQL Tuning Set Name my_sts Task Owner APPS SQL Tuning Set Owner APPS Description Total SQL Statement Count 101 Execution Information Execution Name my_exec_compare Started 05 21 2007 11 30 09 Execution Type ANALYZE PERFORMANCE Last Updated 05 21 2007 11 30 10 Description i Global Time Limit UNLIMITED Scope COMPREHENSIVE Per SQL Time Limit UNUSED Status COMPLETED Number of Errors 0 Analysis Information SQL Impact Threshold 1 Before Change Execution After Change Execution Execution Name my_exec_BEFORE_change Execution
40. SELECT VALUE P FROM table DBMS_SQLTUNE SELECT_SQL_TRACE sql_trace_prod ora P DBMS_SQLTUNE LOAD_SQLSET my_sts_9i cur CLOSE cur END The syntax for the SELECT_SQL_TRACE function is as follows DBMS_SOLTUNE SELECT_SQL_TRACE directory file_name mapping_table_name mapping_table_owner select_mode options pattern_start parttern_end result_limit RETURN sys sqlset PIPELINE IN VARCH IN VARCH IN VARCH IN VARCH IN POSIT I I I R2 R2 NU R2 NULL R2 NU VE SINGLE_EXECUTION N BINARY_INTEGER LIMITED_COMMAND_TYPE N VARCHAR2 NU N VARCHAR2 NULL IN POSITIVE NU D LLG LLG Hp p p p PK LLG LL Table 7 1 describes the available parameters for the SELECT_SQL_TRACE function Table 7 1 DBMS_SQLTUNE SELECT_SQL_TRACE Function Parameters Parameter Description directory file_name mapping_table_name mapping_table_owner Specifies the directory object pointing to the directory where the SQL trace files are stored Specifies all or part of the name of the SQL trace files to process If unspecified the current or most recent trace file in the specified directory will be used wildcards are supported for matching trace file names Specifies the name of the mapping table If set to the default value of NULL mappings from the current database will be used Note that the mapping table
41. SQL Tuning Advisor After tuning the regressed SQL statements you should test these changes using SQL Performance Analyzer Run a new SQL trial on the test system followed by a second comparison between this new SQL trial and the first SQL trial to validate your results Once SQL Performance Analyzer shows that performance has stabilized the testing is complete Implement the fixes from this step to your production system Starting with Oracle Database 11g Release 1 SQL Tuning Advisor performs an alternative plan analysis when tuning a SQL statement SQL Tuning Advisor searches the current system for previous execution plans including the plans from the first SQL trial If the execution plans from the first SQL trial differ from those of the second SQL trial SQL Tuning Advisor will recommend the plans from the first SQL trial If these execution plans produce better performance you can create plan baselines using the plans from the first SQL trial Note SQL Performance Analyzer does not provide the option to create SQL plan baselines or run SQL Tuning Advisor directly after after completing a remote SQL trial In such cases you need to use APIs to manually transport the SQL tuning set and complete the appropriate procedure on the remote database See Also a Oracle Database Performance Tuning Guide for information about alternative plan analysis Creating SQL Plan Baselines Creating SQL plan baselines enables the optim
42. SQL statement The data in this table reveals that this SOL statement is present in both SQL tuning sets but that it has only three execution plans in the first SQL tuning set and two execution plans in the second SQL tuning set Furthermore the SQL statement was executed 22 times in the first SOL tuning set but only 20 times in the second SQL tuning set The Plan Execution Statistics section shows runtime statistics per execution plan or plan hash value The Plans Before Change column lists plans and their associated execution statistics for the first SQL tuning set the Plans After Change columns lists these values for the second SQL tuning set Execution plans structures for both SQL tuning sets are shown at the end of the report You can use these sections in the report to identify changes in execution plans between two SQL tuning sets This is important because changes in execution plans may be a result of test changes that can have a direct impact to performance When comparing two SQL tuning sets SQL Performance Analyzer reports execution plan changes when a SQL statement has a One plan in both SQL tuning sets but the plan structure is different a More than one plan and the number of plans in both SQL tuning sets are The same but at least one plan in the second SQL tuning set is different from all plans in the first SOL tuning set Different After evaluating the SQL statement and plan changes determine if further action
43. This documentation is available in HTML format and contains markup to facilitate access by the disabled community Accessibility standards will continue to evolve over time and Oracle is actively engaged with other market leading technology vendors to address technical obstacles so that our documentation can be accessible to all of our customers For more information visit the Oracle Accessibility Program Web site at http www oracle com accessibility Accessibility of Code Examples in Documentation Screen readers may not always correctly read the code examples in this document The conventions for writing code require that closing braces should appear on an otherwise empty line however some screen readers may not always read a line of text that consists solely of a bracket or brace Accessibility of Links to External Web Sites in Documentation This documentation may contain links to Web sites of other companies or organizations that Oracle does not own or control Oracle neither evaluates nor makes any representations regarding the accessibility of these Web sites vii Access to Oracle Support Oracle customers have access to electronic support through My Oracle Support For information visit http www oracle com support contact html or visit http www oracle com accessibility support html if you are hearing impaired Related Documents For more information about some of the topics discussed in this document see the followi
44. a SQL tuning set in conjunction with SQL Performance Analyzer to gain a more SQL centric analysis of how the change affects SQL statements and execution plans By capturing a SQL tuning set during workload replay you can use SQL Performance Analyzer to compare this SQL tuning set to another SQL tuning set captured during workload capture without having to re execute the SQL statements This enables you to obtain a SQL Performance Analyzer report and compare the SQL performance before and after change while running Database Replay Note Capturing SQL statements into a SQL tuning set is the default and recommended workload replay option 10 Under Identify Source select whether to use default replay options or replay options from a previous replay if one is available If multiple replays exist select the replay you want to use from the Replay Name list Click Next The Replay Workload Customize Options page appears Replay Workload Customize Options Database x090422 Cancel Back Step 2 of 5 l k p 2 of 5 Next Capture Name CAPTURE x090422 20090501115751 Logged InAs IMMCHAN Connection Mappings l Replay Parameters Replay Clients must establish connections to the replay database Specify connection details to the replay database using either a single connect descriptor or net service name Optionally you can map every captured connect descriptor to a separate connect descriptor or net service name for
45. an initialization parameter using the Search and Select Initialization Parameters window b Inthe Base Value field enter the current value of the initialization parameter c Inthe Changed Value field enter the new value of the initialization parameter 8 Inthe Comparison Metric list select the comparison metric to use for the analysis a If you selected Generate Plans in Step 5 then select Optimizer Cost a If you selected Execute SQLs in Step 5 then select one of the following options Elapsed Time CPU Time User I O Time Buffer Gets 3 4 Oracle Database Real Application Testing User s Guide Creating an Analysis Task Using Enterprise Manager Physical I O Optimizer Cost I O Interconnect Bytes To perform the comparison analysis by using more than one comparison metric perform separate comparison analyses by repeating this procedure using different metrics 9 Inthe Schedule section a Inthe Time Zone list select your time zone code b Select Immediately to start the task now or Later to schedule the task to start at a time specified using the Date and Time fields 10 Click Submit The SQL Performance Analyzer page appears In the SQL Performance Analyzer Tasks section the status of this task is displayed To refresh the status icon click Refresh After the task completes the Status field changes to Completed SQL Performance Analyzer Tasks Delete View Latest Report
46. and also recorded in the spfile so that the new setting will persist when the database is restarted If a spfile is not being used the PRE_11G_ENABLE_CAPTURE initialization parameter will only be modified for the currently running instance and the new setting will not persist when the database is restarted To make the setting persistent without using a spfile you will need to manually specify the parameter in the initialization parameter file init ora 9 4 Oracle Database Real Application Testing User s Guide Capturing a Database Workload Using Enterprise Manager Note The PRE_11G_ENABLE_CAPTURE initialization parameter can only be used with Oracle Database 10g Release 2 10 2 This parameter is not valid in subsequent releases After upgrading the database you will need to remove the parameter from the server parameter file spfile or the initialization parameter file init ora otherwise the database will fail to start up See Also a Oracle Database Reference for more information about the PRE_ 11G_ENABLE_CAPTURE initialization parameter Capturing a Database Workload Using Enterprise Manager This section describes how to capture a database workload using Enterprise Manager The primary tool for capturing database workloads is Oracle Enterprise Manager If for some reason Oracle Enterprise Manager is unavailable you can capture database workloads using
47. and the AWR snapshots that correspond to the original capture time period are still available Monitoring Workload Capture Using Views This section summarizes the views that you can display to monitor workload capture You can also use Oracle Enterprise Manager to monitor workload capture as described in Monitoring Workload Capture Using Enterprise Manager on page 9 10 To access these views you need DBA privileges The DBA_WORKLOAD_CAPTURES view lists all the workload captures that have been captured in the current database a The DBA_WORKLOAD_FILTERS view lists all workload filters used for workload captures defined in the current database See Also Oracle Database Reference for information about these views 9 16 Oracle Database Real Application Testing User s Guide 10 Preprocessing a Database Workload After a workload is captured and setup of the test system is complete the captured data must be preprocessed Preprocessing a captured workload creates all necessary metadata for replaying the workload This must be done once for every captured workload before they can be replayed After the captured workload is preprocessed it can be replayed repeatedly ona replay system To preprocess a captured workload you will first need to move all captured data files from the directory where they are stored on the capture system to a directory on the instance where the preprocessing will be perfor
48. both on capture time SCN values as well as database objects to calculate the dependencies among replayed calls The default value is SCN This parameter scales the elapsed time from when the workload capture started to when 100 the session connects with the specified value and is interpreted as a value The parameter controls the rate of logon activity during replay The default value is 100 This parameter scales the elapsed time between two successive user calls from the same 100l session and is interpreted as a value The parameter controls the replayed request rate Thus setting this parameter to 0 will send user calls to the database as fast as possible during replay The default value is 100 think time auto correct This parameter reduces the think time if workload replay goes slower than workload TRUE Seana ae ree capture in an attempt to maintain the captured request rate If this parameter is set to ae TRUE the system will correct the think time based on the think_time_scale parameter between calls when user calls take longer to complete during replay than during capture The default value is TRUE connect_time_scale think_time_scale After setting the replay parameters click Next The Replay Workload Prepare Replay Clients page appears 13 Ensure that replay clients are prepared for replay Before proceeding the replay clients need to be prepared For more information see Setting Up Replay Clients on p
49. data is built you can compare the pre change SQL trial to the post change SQL trial by running a comparison analysis as described in Chapter 6 Comparing SQL Trials Creating a Post Change SQL Trial Using APIs This section describes how to collect the post change SQL performance data using the DBMS_SQLPA EXECUTE_ANALYSIS_TASK procedure Note If you are running the SQL statements remotely on another test system over a database link the remote user calling this procedure needs to have the EXECUTE privilege for the DBMS_SQLPA package Call the EXECUTE_ANALYSIS_TASK procedure using the parameters described in Creating a Pre Change SQL Trial Using APIs on page 4 4 Be sure to specify a different value for the execution_name parameter It is also highly recommended that you create the post change SQL trial using the same method as the pre change SQL trial by using the same value for the execution_type parameter Note If you want to run an Oracle Exadata simulation you should first set the CELL_SIMULATION_ENABLED task parameter to TRUE For more information see Running the Exadata Simulation Using APIs on page 3 14 The following example illustrates a function call made after a system change Creating a Post Change SQL Trial 5 3 Creating a Post Change SQL Trial Using APIs EXEC DBMS_SQLPA EXECUTE_ANALYSIS_TASK task_name gt my_spa_task
50. databases Therefore you should reconfigure all database links to point to an appropriate database that contains the data needed for replay External tables 11 2 Oracle Database Real Application Testing User s Guide Steps for Replaying a Database Workload All external files specified using directory objects referenced by external tables need to be available to the database during replay The content of these files should be the same as during capture and the filenames and directory objects used to define the external tables should also be valid a Directory objects You should reconfigure any references to directories on the production system by appropriately redefining the directory objects present in the replay system after restoring the database m URLs URLs URIs that are stored in the database need to be configured so that Web services accessed during the workload capture will point to the proper URLs during replay If the workload refers to URLs that are stored in the production system you should isolate the test system network during replay a E mails To avoid resending E mail notifications during replay any E mail server accessible to the replay system should be configured to ignore requests for outgoing E mails Tip To avoid impacting other production systems during replay Oracle strongly recommends running the replay within an isolated private network that does not have access to the production environment ho
51. display of the captured session activity compared to the uncaptured session activity such as background activities or filtered sessions This chart will be shown only when there is Active Session History ASH data available for the capture period Under Comparison various statistics for the workload capture are displayed including database time average active sessions user calls transactions connects and application errors The statistics for the total session activity are displayed in the Total column and the statistics for the captured session activity are displayed in the Capture column The Percentage of Total column displays the percentage of total session activity that are being captured in the workload To view the workload capture report click View Workload Capture Report To view workload filters used by the workload capture click the Workload Filters tab Details about the workload filters used by the workload capture are displayed including the workload filter name type session attribute and value To return to the Database Replay page click OK See Also Oracle Database Performance Tuning Guide for information about ASH Capturing a Database Workload Using APIs This section describes how to capture a database workload using APIs You can also use Oracle Enterprise Manager to capture database workloads as described in Capturing a Database Workload Using Enterprise Manager on page 9 5 Capturing a
52. execution plan 4 Review the global statistics as described in Reviewing the SQL Performance Analyzer Report Global Statistics on page 6 5 Reviewing the SQL Performance Analyzer Report Global Statistics The Global Statistics section reports statistics that describe the overall performance of the entire SQL workload This section is a very important part of the SQL Performance Analyzer analysis because it reports on the impact of the system change on the overall performance of the SQL workload Use the information in this section to understand the tendency of the workload performance and determine how it will be affected by the system change To review global statistics 1 Review the chart in the Projected Workload Elapsed Time subsection Note The name of the subsection may vary based on the comparison metric that is selected Comparing SQL Trials 6 5 Comparing SQL Trials Using Oracle Enterprise Manager The chart shows the two trials on the x axis and the elapsed time in seconds on the y axis Projected Workload Elapsed Time eeN wow O o Elapsed Time se M sol Trial 1 W SQL Trial 2 Improvement Impact 20 lt f Regression Impact 2 4 Overall Impact 17 The most important statistic is the overall impact which is given as a percentage The overall impact is the difference between the improvement impact and the regression impact You can click the link for any impact
53. has not been run previously It is strongly recommended that you run Workload Analyzer as part of the workload preprocessing Click Next The Preprocess Captured Workload Schedule page appears Preprocess Captured Workload Schedule Database x112 Cancel Back Step 2 of 3 Next Version 11 2 0 2 0 Capture Name CAPTURE x112 20100726181024 Logged In As IMMCHAN Specify the following information to schedule the preprocessing job Job Parameters x Job Name PREPROCESS X112 20100726183202 Description Start Immediately O Later Date Jul 26 2010 example Jul 26 2010 Time 6_ 30 00 JOAM PM Host Credentials Username limmchan Password eseese Confirm Password leoveee C Save as Preferred Credential 6 Define the parameters for the preprocessing job Preprocessing a Database Workload 10 3 Preprocessing a Database Workload Using APIs a Under Job Parameters enter a name and a description for the job a Under Start select whether the job will run immediately by selecting Immediately or at a later time by selecting Later and specifying the desired time using the Date and Time fields a Under Host Credentials enter the user name and password information for the database host that will used for the preprocessing After defining the job parameters click Next The Preprocess Captured Workload Review page appears Preprocess Capture
54. import export 3 Verify that all prerequisites are met before proceeding For information about the prerequisites see Prerequisites for Capturing a Database Workload on page 9 1 For each verified prerequisite check the box in the Acknowledge column Once all prerequisites are verified click Next The Capture Workload Options page appears Capture Workload Options Database x112 Cancel Back Step 2 of 5 Next Logged InAs IMMCHAN Database Restart Options A database restart prior to a workload capture is recommended to ensure a complete and accurate capture Not restarting could capture in flight transactions which may adversely affect the replay of subsequent captured transactions Do not restart the database prior to the capture O Restart the database prior to the capture SQL Performance Analyzer SQL Performance Analyzer allows you to test and to analyze the effects of changes on the execution performance of SQL contained in a SQL Tuning Set M Capture SQL statements into a SQL Tuning Set during workload capture Workload Filters Workload filters can customize the workload to be captured By default most external client requests made to the database are captured Refer to the Oracle Real Application Testing User s Guide for more information Filter Mode Exclusion M Excluded Sessions All sessions will be captured except for those listed below Session Filter Name Type Attribute Value Remo
55. is required If the SQL statement has regressed perform one of the following actions a Tune the regressed SQL statement as described in Tuning Regressed SQL Statements Using APIs on page 6 22 a Create SQL plan baselines as described in Creating SOL Plan Baselines Using APIs on page 6 26 Tuning Regressed SQL Statements Using APIs After reviewing the SQL Performance Analyzer report you should tune any regressed SQL statements that are identified after comparing the SQL performance If there are 6 22 Oracle Database Real Application Testing User s Guide Comparing SQL Trials Using APIs large numbers of SQL statements that appear to have regressed you should try to identify the root cause and make system level changes to rectify the problem In cases when only a few SQL statements have regressed consider using the SQL Tuning Advisor to implement a point solution for them or creating SQL plan baselines to instruct the optimizer to select the original execution plan in the future To tune regressed SQL statements reported by SOL Performance Analyzer using APIs create a SQL tuning task for the SQL Performance Analyzer execution by using the CREATE_TUNING_TASK function in the DBMS_SQLTUNE package BEGIN DBMS_SQLTUNE CREATE_TUNING_TASK spa_task_name gt my_spa_task spa_task_owner gt immchan spa_compare_exec gt my_exec_compare DBMS_SQLTUNE EXECUTE_TUNING_TASK spa_task_name gt my_s
56. minutes and gather performance data Select Unlimited The execution will run each SQL statement in the SQL tuning set to completion and gather performance data Collecting execution statistics provides greater accuracy in the performance analysis but takes a longer time Using this setting is not recommended because the task may be stalled by one SQL statement for a prolonged period a Select Customize and enter the specified number of seconds minutes or hours Ensure that the database environment on the test system matches the production environment as closely as possible and select Trial environment established In the Schedule section a Inthe Time Zone list select your time zone code b Select Immediately to start the task now or Later to schedule the task to start at a time specified using the Date and Time fields Click Submit The Guided Workflow page appears when the execution begins The status icon of this step changes to a clock while the execution is in progress To refresh the status icon click Refresh Depending on the options selected and the size of the SQL workload the execution may take a long time to complete After the execution is completed the Status icon will change to a check mark and the Execute icon for the next step is enabled Once the pre change performance data is built you can make the system change and build the post change performance data by re executing the SQL statements in the SQL tu
57. monitor workload replay as described in Monitoring Workload Replay Using Enterprise Manager on page 11 13 This section contains the following topics a Retrieving Information About Diverged Calls Monitoring Workload Replay Using Views Retrieving Information About Diverged Calls During replay any error and data discrepancies between the replay system and the capture system are recorded as diverged calls To retrieve information about a diverged call including its SQL identifier SQL text and bind values call the GET_DIVERGING_STATEMENT function using the following parameters a Set the replay_id parameter to the ID of the replay in which the call diverged Set the stream_id parameter to the stream ID of the diverged call Set the call_counter parameter to the call counter of the diverged call To view these information about a diverged call use the DBA_WORKLOAD_REPLAY_ DIVERGENCE view The following example illustrates a function call EXEC DBMS WORKLOAD REPLAY GET_DIVERGENT_STATEMENT replay_id gt 1 stream_id gt 3 call_counter gt 5 See Also Oracle Database PL SQL Packages and Types Reference for information about the DBMS_WORKLOAD_REPLAY package Monitoring Workload Replay Using Views This section summarizes the views that you can display to monitor workload replay You need DBA privileges to access these views a The DBA_WORKL
58. of gv7xb8tyd1v91 A performance impact on the workload of 33 1 based on the change No performance impact on the SQL statement based on the change because its Total Metric After change value is missing D New SQL This category represents all SQL statements that are present in the second SQL tuning set but are not found in the first SQL tuning set In this example only two Comparing SQL Trials 6 19 Comparing SQL Trials Using APIs SQL statements are new in the second SQL tuning set As shown in Example 6 9 these SQL statements have sql_id values of 4c8nrqxhtb2sf and 9utadgu5udmh4 A total performance impact on the workload of 8 48 Missing Total Metric Before change values Example 6 9 shows a table in the sample report that lists the missing and new SQL statements as well as other top SQL statements as determined by their impact on the workload Example 6 9 Top 7 SQL Sorted by Absolute Value of Change Impact on the Workload Top 7 SQL Sorted by Absolute Value of Change Impact on the Workload Impact on Total Metric Total Metric Impact Plan sql_id Workload Before After on SQL Change Tgj3w9ya4d9sj 41 04 812791 36974 953 y gv7xb8tyd1v91 33 1 625582 n 4c8nrqxhtb2sf 8 35 157782 n 22u3tvrt0yr6g 4 58 302190 215681 28 63 n fgdd0fd56qmt0 2 1 146128 106369 27 21 n 9utadgu5udmh4 13 2452 n 4dtv43awxnmv3 02 3520 3890 47 35 n Once you have identified a SQL statement of in
59. running the wrc executable in replay mode on the hosts where they are installed Once started each replay client will initiate one or more sessions with the database to drive the workload replay In replay mode the wrc executable accepts the following keywords userid and password specify the user ID and password of a replay user for the replay client If unspecified these values default to the system user a server specifies the connection string that is used to connect to the replay system If unspecified the value defaults to an empty string xveplaydir specifies the directory that contains the preprocessed workload capture you want to replay If unspecified it defaults to the current directory a workdir specifies the directory where the client logs will be written This parameter is only used with the debug parameter for debugging purposes a debug specifies whether debug data will be created Possible values include on Debug data will be written to files in the working directory 11 6 Oracle Database Real Application Testing User s Guide Steps for Replaying a Database Workload off No debug data will be written the default value Note Before running the wrc executable in debug mode contact Oracle Support for more information connection_override specifies whether to override the connection mappings stored in the DBA_WORKLOAD_CONNECTION_MAP view If set to TRUE connection remappings stor
60. system The following example executes the SQL Performance Analyzer task named my_spa_ task and performs a test execute of the SQL statements remotely over a database link EXEC DBMS_SQLPA EXECUTE_ANALYSIS_TASK task_name gt my_spa_task execution_type gt TEST EXECUTE execution_name gt my_remote_trial_10g execution_params gt dbms_advisor arglist database_link LINK A B C BIZ COM To build the post upgrade SQL trial using APIs perform an explain plan or test execute using the SQL Performance Analyzer system by calling the EXECUTE_ ANALYSIS_TASK procedure with the DATABASE_LINK task parameter set to the global name of a public database link connecting to a user with the EXECUTE privilege for the DBMS_SQLPA package and the ADVISOR privilege on the test system If you choose to use EXPLAIN PLAN only execution plans will be generated Subsequent comparisons will only be able to yield a list of changed plans without making any conclusions about performance changes If you choose to use TEST EXECUTE the SQL workload will be executed to completion This effectively builds the post upgrade SQL trial using the statistics and execution plans generated from the test system Using TEST EXECUTE is recommended to capture the SQL execution plans and performance data at the source thereby resulting in a more accurate analysis
61. the following sections a Using Workload Capture Reports a Using Workload Replay Reports Using Compare Period Reports Note After the replay analysis is complete you can restore the database to its original state at the time of workload capture and repeat workload replay to test other changes to the system once the workload directory object is backed up to another physical location Using Workload Capture Reports Workload capture reports contain captured workload statistics information about the top session activities that were captured and any workload filters used during the capture process The following sections describe how to generate and utilize workload capture reports Generating Workload Capture Reports Using Enterprise Manager a Generating Workload Capture Reports Using APIs a Reviewing Workload Capture Reports Generating Workload Capture Reports Using Enterprise Manager This section describes how to generate a workload capture report using Oracle Enterprise Manager The primary tool for generating workload capture reports is Oracle Enterprise Manager If for some reason Oracle Enterprise Manager is unavailable you can generate workload capture reports using APIs as described in Generating Workload Capture Reports Using APIs on page 12 2 To generate a workload capture report using Enterprise Manager 1 On the Software and Support page under Real Application Testing click Database Replay
62. the test system Alternatively click the search icon to search for and select a database link or click Create Database Link to create a database link using the Create Database Link page 7 Inthe Comparison Metric list select the comparison metric to use for the comparison analysis Elapsed Time CPU Time User I O Time Buffer Gets Physical I O Optimizer Cost I O Interconnect Bytes Optimizer Cost is the only comparison metric available if you generated execution plans only in the SQL trials To perform the comparison analysis by using more than one comparison metric perform separate comparison analyses by repeating this procedure with different metrics 8 Under Schedule a Inthe Time Zone list select your time zone code b Select Immediately to start the task now or Later to schedule the task to start at a time specified using the Date and Time fields 9 Click Submit The SQL Performance Analyzer page appears In the SQL Performance Analyzer Tasks section the status of this task is displayed To refresh the status icon click Refresh After the task completes the Status field changes to Completed 10 Under SQL Performance Analyzer Tasks select the task and click the link in the Name column The SQL Performance Analyzer Task page appears This page contains the following sections 7 8 Oracle Database Real Application Testing User s Guide Upgrading from Oracle9i Database
63. to Completed SQL Performance Analyzer Tasks Delete View Latest Report Current Step SQLs Steps Select Name Owner _ Last Modified Y Name Type Status Processed Completed SPA _EXADATA SIM IMMCHAN an 3 2009 4 50 48 EXEC 12 Compare Completed 1543 of 1543 4 of 4 8 In the SQL Performance Analyzer Tasks section select the task and click the link in the Name column The SQL Performance Analyzer Task page appears SQL Performance Analyzer Task IMMCHAN SPA_EXADATA_SIM View Latest Report Page Refreshed Jun 3 2009 5 06 40 AM PDT Refresh The SQL Performance Analyzer Task is a container for experimental results of executing a specific SQL Tuning Set under changed lenvironmental conditions and assessing the impact of environmental changes on STS execution performance SQL Tuning Set Y SQL Trials A SQL Trial captures the execution performance of the SQL Tuning Set under specific environmental conditions SQL Trial Name Description Created SQL Executed Status INITIAL_SQL_TRIAL Exadata Storage Server simulation disabled 6 3 09 4 49AM Yes COMPLETED SECOND_SQL_TRIAL Exadata Storage Server simulation enabled 6 3 09 4 50 AM Yes COMPLETED Y SQL Trial Comparisons Compare SQL Trials to assess change impact of environmental differences on SQL Tuning Set execution costs Trial 1 Name Trial 2 Name Compare Metric Created Status Comparison Report INTTIAL_SQL_TRIAL SECOND_SQL_TRIAL O Interconnect Bytes 6 3 09 4 50 AM COMPLETED o
64. to or information on content products and services from third parties Oracle Corporation and its affiliates are not responsible for and expressly disclaim all warranties of any kind with respect to third party content products and services Oracle Corporation and its affiliates will not be responsible for any loss costs or damages incurred due to your access to or use of third party content products or services Contents PAG emanon Sshnn Besse eases a lees tee Tess cass tec a sch ended a ari cedh E Bashan N vii Audience eenean vet aeouds doce beth eda siecle sdeiocsttatelecbodbeudretesiovetabeh lectus bdesh tole aaa vii Documentation Accessibility ssyon tenres a e aee g en a vii Related Documents erone iera a a a a aa a a ea a a o sda soit ees viii Roa NAE a ALOI A E ENEE EETA A A E E TE I S EE TT viii 1 introduction to Oracle Real Application Testing SOL Performance Analy Zen v ccc ccsssesevccsseccnetseiecevevisesesevesoutsesevesestatecsessetoncsusotetosvenesiereevededtessdbecntecs 1 1 Database Replay cijnen nere earra aikaa oane ahi aesae EE Ea pAr oipe ab beuesbuecehenonesbesb tis 1 2 Part SQL Performance Analyzer 2 Introduction to SQL Performance Analyzer Capturing the SOL Workload is 5 0e ccocsesccusctesthcsecatdhsasdes e E S eea EA EVEA EE Sa TE 2 3 Setting Up the Test Systenn iiss ccceccectseteccencsieedactecssevescctedeces ti ienei e a E E i 2 4 Creating a SQL Performance Analyzer Task cccceeee
65. use the think_time_scale parameter to scale user think time during replay If user calls are being executed slower during replay than during capture you can make the database replay attempt to catch up by setting the think_time_auto_ correct parameter to TRUE This will make the replay client shorten the think time between calls so that the overall elapsed time of the replay will more closely match the captured elapsed time If user calls are being executed faster during replay than during capture setting the think_time_auto_correct parameter to TRUE will not change the think time The replay client will not increase the think time between calls to match the captured elapsed time Using Filters with Workload Replay By default all captured database calls are replayed during workload replay You can use workload filters to specify which database calls to include in or exclude from the workload during workload replay Workload replay filters are first defined and then added to a replay filter set so they can be used in a workload replay There are two types of workload filters inclusion filters and exclusion filters Inclusion filters enable you to specify database calls that will be replayed Exclusion filters enable you to specify database calls that will not be replayed You can use either inclusion filters or exclusion filters in a workload replay but not both The workload filter is determined as an inclusion or exclusion filter wh
66. very important part of the SQL Performance Analyzer analysis because it shows the impact of the system change on the overall performance of the SQL workload Use the information in this section to understand the change of the workload performance and determine whether the workload performance will improve or degrade after making the system change Comparing SQL Trials 6 13 Comparing SQL Trials Using APIs Example 6 2 shows the Overall Performance Statistics subsection of a sample report Example 6 2 Overall Performance Statistics Report Summary Overall Impact Hy 47 94 Improvement Impact 58 02 Regression Impact 10 08 SQL Statement Count SQL Category SQL Count Plan Change Count Overall 101 6 Improved 2 2 Regressed 1 1 Unchanged 98 3 This example indicates that the overall performance of the SQL workload improved by 47 94 even though regressions had a negative impact of 10 08 This means that if all of the regressions are fixed in this example the overall change impact will be 58 02 After the system change 2 of the 101 SQL statements ran faster while 1 ran slower Performance of 98 statements remained unchanged Performance Statistics of SQL Statements The Performance Statistics subsection highlights the SQL statements that are the most impacted by the system change The pre change and post change performance data for each SQL statement in the workload are compared based on the following criteria a Executi
67. will be misleading because the SQL statement will be reported as a regression when in fact it is not Creating an Analysis Task 3 9 Creating an Analysis Task Using Enterprise Manager Note The Exadata simulation workflow is used to simulate an Exadata Storage Server installation on non Exadata hardware To test changes on Exadata hardware use the standard SQL Performance Analyzer workflows Note The Exadata simulation is supported for DSS and data warehouse workloads only To use the SQL Performance Analyzer Exadata simulation workflow 1 On the SQL Performance Analyzer page under SQL Performance Analyzer Workflows click Exadata Simulation The Exadata Simulation page appears Exadata Simulation Task Information Task Name SQL Tuning Set l Description Creation Method Execute SQLs Per SQL Time Limit 5 minutes TIP Time limit is on elapsed time of test execution of SQL Trial Comparison Comparison Metric I O Interconnect Bytes Schedule Time Zone America Los_Angeles Immediately O Later Date dun 3 2009 example Jun 3 2009 Time 7 02 15 M am OPM 2 Inthe Task Name field enter the name of the task 3 Inthe SQL Tuning Set field enter the name of the SQL tuning set that contains the SQL workload to be analyzed Alternatively click the search icon to search for a SQL tuning set using the Search a
68. 003195 cpu_time 00957 0012 0032 0005 0032 buffer_gets 18 0 5 0 5 reads 0 0 0 0 0 writes 0 0 0 0 0 rows 0 0 0 0 0 Execution Plans Before Change Plan Hash Value 440231712 Id Operation Name Rows Bytes Cost Time 0 SELECT STATEMENT 2 1 PX COORDINATOR 2 PX SEND QC RANDOM TQ10000 1 87 2 00 00 01 3 PX BLOCK ITERATOR 1 87 2 00 00 01 4 TABLE ACCESS FULL EMP 1 87 2 00 00 01 Note dynamic sampling used for this statement Plan Hash Value 571903972 Id Operation Name Rows Bytes Cost Time 0 SELECT STATEMENT t 1 TABLE ACCESS BY INDEX ROWID EMP 1 87 1 00 00 01 2 INDEX UNIQUE SCAN My_EMP_IDX 1 0 Plan Hash Value 3634526668 Id Operation Name Rows Bytes Cost Time 0 SELECT STATEMENT l 2 1 TABLE ACCESS FULL EMP ON 87 2 00 00 01 dynamic sampling used for this statement Executions Plan After Change Comparing SQL Trials 6 21 Comparing SQL Trials Using APIs Plan Hash Value 571903972 Id Operation Name Rows Bytes Cost Time 0 SELECT STATEMENT 1 1 TABLE ACCESS BY INDEX ROWID EMP se 87 1 00 00 01 2 INDEX UNIQUE SCAN MY_EMP_IDX 1 0 Id Operation Name Rows Bytes Cost Time 0 SELECT STATEMENT 2 1 TABLE ACCESS FULL EMP 1 87 2 00 00 01 Note The SQL Execution Statistics section shows the average runtime statistics per execution of the
69. 1 2009 example May 1 2009 Time 2 m 21 0 7 Oam em In this example the SQL_TRIAL_1241213421833 and SQL_TRIAL_ 1241213881923 trials are selected for comparison 2 To compare trials other than those listed by default select the desired trials in the Trial 1 Name and Trial 2 Name lists Note that you cannot compare a statistical trial with a trial that tests the explain plan only 3 In the Comparison Metric list select the comparison metric to use for the comparison analysis Elapsed Time CPU Time User I O Time 6 2 Oracle Database Real Application Testing User s Guide Comparing SQL Trials Using Oracle Enterprise Manager Buffer Gets Physical I O Optimizer Cost I O Interconnect Bytes Optimizer Cost is the only comparison metric available if you generated execution plans only in the SQL trials To perform the comparison analysis by using more than one comparison metric perform separate comparison analyses by repeating this procedure with different metrics 4 Inthe Schedule section a Inthe Time Zone list select your time zone code b Select Immediately to start the task now or Later to schedule the task to start at a time specified using the Date and Time fields 5 Click Submit The Guided Workflow page appears when the comparison analysis begins The status icon of this step changes to an arrow icon while the comparison analysis is in progress To re
70. 26185136 Jul 26 2010 7 04 29 PM 1x Run Replay Compare Period Report Run AWR Compare Period Report Run SQL Performance Analyzer Report AWR Report Workload Capture or Replay REPLAY x112 20100726185136 Jul 26 2010 7 04 29 PM x Run Report ASH Report Workload Capture or Replay REPLAY x112 20100726185136 Jul 26 2010 7 04 29 PM x Start Date Jul 26 2010 End Date Jul 26 2010 example Jul 26 2010 example Jul 26 2010 Stat Time 7 04 OAM PM EndTime 7 _i 09 4 OAM PM Filter SID E Run Report There are several types of reports you can run for a completed workload replay a Workload Replay The Workload Replay report contains information that can be used to measure data and performance divergence between the capture system and the replay system To run this report under Workload Replay Report click Run Report For information about using the Workload Replay report see Reviewing Workload Replay Reports on page 12 5 Replay Compare Period The Replay Compare Period report can be used to compare one workload replay to its capture or to another replay of the same capture Before running this report AWR data for the captured or replayed workload must have been previously exported To run this report under Compare Period Report select the first and second workload captures or replays you want to compare and click Run Rep
71. 79 Operation Name Rows Bytes Cost Time SELECT STATEMENT 126 2771 00 00 34 HASH GROUP BY 126 2771 00 00 34 NESTED LOOPS 126 2770 00 00 34 HASH JOIN 111 2722 00 00 33 HASH JOIN 100 2547 00 00 31 TABLE ACCESS FULL LU_ELEMENTGROUP_REL 11 162 00 00 02 NESTED LOOPS NESTED LOOPS 484 43076 2384 00 00 29 HASH JOIN 14 770 741 00 00 09 NESTED LOOPS 4 124 683 00 00 09 TABLE ACCESS FULL LU_ELEMENTRANGE_REL L 15 35 00 00 01 TABLE ACCESS FULL ADM_PG_FEATUREVALUE 4 64 649 00 00 08 TABLE ACCESS FULL LU_ITEM_293 5355 128520 56 00 00 01 BITMAP CONVERSION TO ROWIDS BITMAP INDEX SINGLE VALUE FACT_274_ITEM_IDX TABLE ACCESS BY INDEX ROWID FACT_PD_OUT_ITM_293 36 1224 2384 00 00 29 TABLE ACCESS FULL LU_ELEMENTGROUP_REL 123 1353 175 00 00 03 TABLE ACCESS FULL LU_ELEMENTRANGE_REL 1 15 49 00 00 01 Comparing SQL Tuning Sets Using APIs You can compare two SQL tuning sets using SQL Performance Analyzer APIs For example while using Database Replay you may have captured a SQL tuning set on the production system during workload capture and another SQL tuning set on a test system during workload replay You can then use SQL Performance Analyzer to compare these SQL tuning sets without having to re execute the SQL statements This is useful in cases where you already have another utility to run your workload before and after making the system change such as a custom script When comparing SQL tuning sets SQL Performance Analyzer u
72. 8 38 P 20090604035557 PDT AM PDT REPLAY x112 Completed 00 02 07 Jun 4 2009 3 35 47 AM Jun 4 2009 3 37 54 20090604033037 PDT AM PDT For information about how to interpret the workload replay report see Reviewing Workload Replay Reports on page 12 5 Generating Workload Replay Reports Using APIs This section describes how to generate a workload replay report using the DBMS_ WORKLOAD_REPLAY package You can also use Oracle Enterprise Manager to generate a workload replay report as described in Generating Workload Replay Reports Using Enterprise Manager on page 12 3 To generate a report on the latest workload replay for a workload capture use the DBMS_WORKLOAD_REPLAY GET_REPLAY_INFO procedure and the REPLAY REPORT function DECLARE cap_id NUMBER rep_id NUMBER rep_rpt CLOB BEGIN cap_id DBMS WORKLOAD _REPLAY GET_REPLAY_INFO dir gt dec06 Get the latest replay for that capture SELECT max id INTO rep_id FROM dba_workload_replays WHERE capture_id cap_id rep_rpt DBMS _WORKLOAD_REPLAY REPORT replay_id gt rep_id DI BMS_WORKLOAD format gt DBMS_WORKLOAD_REPLAY TYPE_TEXT END In this example the GET_REPLAY_INFO procedure retrieves all information regarding the workload capture in the dec06 directory and the history of all the workload 12 4 Oracle Database Real Application Testing User s Guide Using Workload Replay
73. ABLE from the user s schema on the test system Once the upgrade environment is configured as described perform the steps as described in the following procedure to use SQL Performance Analyzer in a database upgrade from Oracle9i or Oracle Database 10g Release 1 to a newer release 1 Enable the SQL Trace facility on the production system as described in Enabling SQL Trace on the Production System on page 7 3 To minimize the performance impact on the production system and still be able to fully capture a representative set of SQL statements consider enabling SQL Trace for only a subset of the sessions for as long as required to capture all important SQL statements at least once 7 2 Oracle Database Real Application Testing User s Guide Upgrading from Oracle9i Database and Oracle Database 10g Release 1 On the production system create a mapping table as described in Creating a Mapping Table on page 7 4 This mapping table will be used to convert the user and object identifier numbers in the SQL trace files to their string equivalents Move the SQL trace files and the mapping table from the production system to the SQL Performance Analyzer system as described in Creating a Mapping Table on page 7 4 On the SQL Performance Analyzer system construct a SQL tuning set using the SQL trace files as described in Building a SQL Tuning Set on page 7 4 The SQL tuning set will contain the SQL st
74. APIs as described in Capturing a Database Workload Using APIs on page 9 13 To capture a database workload using Enterprise Manager 1 On the Software and Support page under Real Application Testing click Database Replay The Database Replay page appears Database Replay Database Replay allows workloads to be captured from production Page Refreshed May 1 2009 11 05 14 AM po acy systems and re executed with high fidelity on test copies of production PDT esl databases This enables detailed analysis of how the proposed changes may affect production systems for instance patching or upgrading database software Go Overview Task to The following are the typical steps to perform Database Replay Task Name Description Task 1 Capture Capture a workload fs 1 Capture the workload on a database Task 1 Workload from the production u 2 Optionally export the AWR data Task 1 environment This can 3 Restore the replay database on a test system to match the capture database be scheduled to at the start of the workload capture Make changes such as perform an upgrade to the test system as needed Copy the captured workload to the test system Preprocess the captured workload Task 2 Configure the test system for the replay Replay the workload on the restored database Task 3 accommodate a database restart if desired 2 Preprocess Preprocessing prepares 5 Workload a captured workload for repla
75. Code None SQL Tuning Set Name CAPTURE_x112_20100509 c_119590 Capture Error Message None Capture Details Replay History Select Name Status Duration hh mm ss Start Time End Time AWR Data Exported No items found 11 8 Oracle Database Real Application Testing User s Guide Replaying a Database Workload Using Enterprise Manager The Capture Summary section displays information about the preprocessed workload capture in the selected directory 4 To view additional details about the workload capture expand Capture Details The Capture Details section displays the workload profile and workload filters used during the workload capture If a Workload Analyzer report was created for the workload click View Workload Analyzer Report to view it 5 Click Set Up Replay The Replay Workload Prerequisites page appears 6 Verify that all prerequisites are met before proceeding For more information about the prerequisites see Steps for Replaying a Database Workload on page 11 2 If you are replaying the workload on a test system ensure that the test system is properly prepared for replay For more information see Setting Up the Test System on page 11 1 Once all prerequisites are completed click Continue The Replay Workload References to External Systems page appears 7 Verify potential references to all external systems and modify any invalid references Use the links available on the Replay Workload References
76. Creating SQL Plan Baselines Using APIs ccccesessesssssssssesssesesseesescsssesesescscsssesesescsessseseeces 6 26 Using SQL Performance Analyzer VieWS cccccccsesesssssssseesssssssssessssssssesesesssssesesesesessesesssees 6 26 Testing a Database Upgrade Upgrading from Oracle9i Database and Oracle Database 10g Release 1 0 cee 7 1 Enabling SQL Trace on the Production System ccccceccsssssesesescsssesesescsesssesescscssseesescssssseesecesens 7 3 Creating asMapping Table i cscct bss unset lutstectarttebswsucrats e ee i E E E E 7 4 Building a SQl Tuning Seti iris eni or eE ie al Reh diesel eae 7 4 Testing Database Upgrades from Oracle9i Database and Oracle Database 10g Release 1 7 6 Upgrading from Oracle Database 10g Release 2 and Newer Releases ccceeees 7 10 Testing Database Upgrades from Oracle Database 10g Release 2 and Newer Releases 7 11 Tuning Regressed SQL Statements After Testing a Database Upgrade 7 15 Part ll Database Replay 8 Introduction to Database Replay Workload Capture i 2 3 ii 2 iain aos sateen One Ga a ae ated ada aaa S 8 2 Workload Preprocessing si s scsccicisietssssiseest teases besbieis thi cccvesedal ince sisassbashststsaviassbasdivsosseadbavscustavasvicseseiee 8 3 Workload Replays cc s 0scsccesctesesccanccesesertecses a Vas tases dan R E E E R E e 8 3 An alysisand Reporting crpio e e E e E G E E e EE 8 3 Capturing a Database Workload Prere
77. Current Step SQLs Steps Select Name Owner Last Modified lt Name Type Status Processed Completed SPA PARAM CHANGE IMMCHAN May 1 2009 2 08 47 EXEC_258 Compare Completed 1134 of 1134 4 of 4 PM 11 In the SQL Performance Analyzer Tasks section select the task and click the link in the Name column The SQL Performance Analyzer Task page appears SQL Performance Analyzer Task IMMCHAN SPA_PARAM_CHANGE View Latest Report Page Refreshed May 1 2009 2 14 03 PM PDT Refresh The SQL Performance Analyzer Task is a container for experimental results of executing a specific SQL Tuning Set under changed environmental conditions and assessing the impact of environmental changes on STS execution performance gt SQL Tuning Set YW SQL Trials A SQL Trial captures the execution performance of the SQL Tuning Set under specific environmental conditions Create SQL Trial SQL Trial Name Description Created SQL Executed Status INITIAL_SQL_TRIAL parameter sort_area_size set to 1048576 5 1 09 2 08 PM Yes COMPLETED SECOND_SQL_TRIAL parameter sort_area_size set to 2097152 5 1 09 2 08 PM Yes COMPLETED Y SQL Trial Comparisons Compare SQL Trials to assess change impact of environmental differences on SQL Tuning Set execution costs Run SQL Trial Comparison Compare Comparison SQL Tune Trial 1 Name Trial 2 Name Metric Created Status Report Report INITIAL_SQL_TRIAL SECOND_SQL_TRIAL Elapsed Time 5 1 09 2 08 COMPLETED pe PM T
78. Database Startup Parameters Startup using current spfile Specify parameter file pfile on database host Specify the fully qualified name for the pfile 5 Define the parameters for the workload capture a Under Workload Capture Parameters in the Capture Name field enter a name for the workload capture In the Directory Object list select the directory where the captured workload will be stored You must select a directory that does not already contain a workload capture For more information see Setting Up the Capture Directory on page 9 3 Capturing a Database Workload 9 7 Capturing a Database Workload Using Enterprise Manager To create a directory object click Create Directory Object The Create Directory Object page appears In the Name field enter a name for the directory object In the Path field enter the path to the directory object To test if the directory exists in the file system click Test File System If the directory does not exist it will need to be created first a Under Database Shutdown Parameters select the type of database shutdown method to perform This option only appears if the database will be restarted before workload capture The types of available database shutdown methods include Immediate An immediate shutdown will roll back all active transactions and discon nect all connected users before shutting down the database Transactional A transactional shutdown wi
79. ING_TASK sqlset_name gt sts_name sqlset_owner gt sts_owner task_name gt tune_task_name EXEC DBMS SQLTUNE SET_TUNING_TASK_PARAMETER tname APPLY CAPTURED _COMPILENV FALSE exec_name DBMS_SQLTUNE EXECUTE_TUNING_TASK tname END Note The APPLY_CAPTURED_COMPILENV parameter used in this example is only supported by Oracle Database 11g Release 1 and newer releases If you are testing a database upgrade from an earlier version of Oracle Database SQL Tuning Advisor will use the environment variables stored in the SQL tuning set instead Comparing SQL Trials 6 25 Comparing SQL Trials Using APIs After tuning the regressed SQL statements you should test these changes using SQL Performance Analyzer Run a new SQL trial on the test system followed by a second comparison between this new SQL trial and the first SQL trial to validate your results Once SQL Performance Analyzer shows that performance has stabilized implement the fixes from this step to your production system See Also a Oracle Database Performance Tuning Guide for information about using the SQL Tuning Advisor and transporting SQL tuning sets a Oracle Database PL SQL Packages and Types Reference for information about the DBMS_SQLTUNE package Creating SQL Plan Baselines Using APIs Creating SQL plan baselines for regressed SQL statements with plan changes is another option to running the SQL Tunin
80. In cases when the performance regressed this section also contains findings on root causes and symptoms Example 6 7 shows the Execution Plans subsection of a sample report Example 6 7 Execution Plans Execution Plan Before Change Plan Id Plan Hash Value 3412943215 Operation Name Rows Bytes Cost Time SELECT STATEMENT 1 126 11224 00 02 15 HASH GROUP BY ul 126 11224 00 02 15 NESTED LOOPS 1 126 11223 00 02 15 HASH JOIN 1 111 11175 00 02 15 TABLE ACCESS FULL LU_ELEMENTGROUP_REL 1 11 162 00 00 02 HASH JOIN 487 48700 11012 00 02 13 MERGE JOIN 14 924 1068 00 00 13 6 16 Oracle Database Real Application Testing User s Guide Comparing SQL Trials Using APIs COMO WAND UNFWNHN RFP OW OW I Executi Plan I Plan Hash Value SORT JOIN 5391 274941 1033 00 00 13 HASH JOIN 5391 274941 904 00 00 11 TABLE ACCESS FULL LU_ELEMENTGROUP_REL 123 1353 175 00 00 03 HASH JOIN 5352 214080 729 00 00 09 TABLE ACCESS FULL LU_ITEM_293 5355 128520 56 00 00 01 TABLE ACCESS FULL ADM_PG_FEATUREVALUE 1629 26064 649 00 00 08 FILTER SORT JOIN 1 15 36 00 00 01 TABLE ACCESS FULL LU_ELEMENTRANGE_REL 1 15 35 00 00 01 INLIST ITERATOR TABLE ACCESS BY INDEX ROWID FACT_PD_OUT_ITM_293 191837 6522458 9927 00 02 00 BITMAP CONVERSION TO ROWIDS BITMAP INDEX SINGLE VALUE FACT_274_PER_IDX TABLE ACCESS FULL LU_ELEMENTRANGE_REL 1 15 49 00 00 01 on Plan After Change d 102 19231456
81. L statement in the SQL tuning set up to 5 minutes and gather performance data 5 2 Oracle Database Real Application Testing User s Guide Creating a Post Change SQL Trial Using APIs Select Unlimited The execution will run each SQL statement in the SQL tuning set to completion and gather performance data Collecting execution statistics provides greater accuracy in the performance analysis but takes a longer time Using this setting is not recommended because the task may be stalled by one SQL statement for a prolonged time period Select Customize and enter the specified number of seconds minutes or hours 6 Ensure that the system change you are testing has been performed on the test system and select Trial environment established 7 Inthe Schedule section a Inthe Time Zone list select your time zone code b Select Immediately to start the task now or Later to schedule the task to start at a time specified using the Date and Time fields 8 Click Submit The Guided Workflow page appears when the execution begins The status icon of this step changes to a clock while the execution is in progress To refresh the status icon click Refresh Depending on the options selected and the size of the SQL workload the execution may take a long time to complete After the execution is completed the Status icon will change to a check mark and the Execute icon for the next step is enabled 9 Once the post change performance
82. OAD_CAPTURES view lists all the workload captures that have been captured in the current database The DBA_WORKLOAD FILTERS view lists all workload filters for workload captures defined in the current database 11 26 Oracle Database Real Application Testing User s Guide Monitoring Workload Replay Using APIs The DBA_WORKLOAD_REPLAYS view lists all the workload replays that have been replayed in the current database The DBA_WORKLOAD_REPLAY_DIVERGENCE view enables you to view information about diverged calls such as the replay identifier stream identifier and call counter The DBA_WORKLOAD REPLAY FILTER_SET view lists all workload filters for workload replays defined in the current database The DBA_WORKLOAD_CONNECTION_MAP view lists the connection mapping information for workload replay The VSWORKLOAD_ REPLAY THREAD view lists information about all sessions from the replay clients See Also a Oracle Database Reference for information about these views Replaying a Database Workload 11 27 Monitoring Workload Replay Using APIs 11 28 Oracle Database Real Application Testing User s Guide 12 Analyzing Replayed Workload There are three types of reports for Database Replay workload capture workload replay and compare period This chapter describes how to generate and analyze these reports and contains
83. ORACLE Oracle Database Real Application Testing User s Guide 11g Release 2 11 2 E16540 03 October 2010 Oracle Database Real Application Testing User s Guide 11g Release 2 11 2 E16540 03 Copyright 2008 2010 Oracle and or its affiliates All rights reserved Primary Author Immanuel Chan Contributors Ashish Agrawal Lance Ashdown Pete Belknap Supiti Buranawatanachoke Romain Colle Karl Dias Kurt Engeleiter Leonidas Galanis Prabhaker Gongloor Shantanu Joshi Mughees Minhas Valarie Moore Yujun Wang Keith Wong Khaled Yagoub Hailing Yu This software and related documentation are provided under a license agreement containing restrictions on use and disclosure and are protected by intellectual property laws Except as expressly permitted in your license agreement or allowed by law you may not use copy reproduce translate broadcast modify license transmit distribute exhibit perform publish or display any part in any form or by any means Reverse engineering disassembly or decompilation of this software unless required by law for interoperability is prohibited The information contained herein is subject to change without notice and is not warranted to be error free If you find any errors please report them to us in writing If this software or related documentation is delivered to the U S Government or anyone licensing it on behalf of the U S Government the following notice is applicable U S G
84. OVERNMENT RIGHTS Programs software databases and related documentation and technical data delivered to U S Government customers are commercial computer software or commercial technical data pursuant to the applicable Federal Acquisition Regulation and agency specific supplemental regulations As such the use duplication disclosure modification and adaptation shall be subject to the restrictions and license terms set forth in the applicable Government contract and to the extent applicable by the terms of the Government contract the additional rights set forth in FAR 52 227 19 Commercial Computer Software License December 2007 Oracle USA Inc 500 Oracle Parkway Redwood City CA 94065 This software is developed for general use in a variety of information management applications It is not developed or intended for use in any inherently dangerous applications including applications which may create a risk of personal injury If you use this software in dangerous applications then you shall be responsible to take all appropriate fail safe backup redundancy and other measures to ensure the safe use of this software Oracle Corporation and its affiliates disclaim any liability for any damages caused by use of this software in dangerous applications Oracle is a registered trademark of Oracle Corporation and or its affiliates Other names may be trademarks of their respective owners This software and documentation may provide access
85. PLAY package Reviewing Workload Replay Reports After the workload is replayed on a test system there may be some divergence in what is replayed compared to what was captured There are numerous factors that can cause replay divergence which can be analyzed using the workload replay report The information contained in the workload replay report consists of performance and replay divergence Performance divergence may result when new algorithms are introduced in the replay system that affect the overall performance of the database For example if the workload is replayed on a newer version of Oracle Database a new algorithm may cause specific requests to run faster and the divergence will appear as a faster execution In this case this is a desirable divergence Data divergence occurs when the results of DML or SQL queries do not match results that were originally captured in the workload For example a SQL statement may return fewer rows during replay than those returned during capture Error divergence occurs when a replayed database call a Encounters a new error that was not captured a Does not encounter an error that was captured a Encounters a different error from what was captured The information contained in the workload replay report are divided into the following categories a Details about the workload replay and the workload capture such as job name status database information duration and time of each p
86. Replay Filter Set Adding Workload Replay Filters To add a new filter to be used in a replay filter set use the ADD_FILTER procedure BEGIN DBMS_WORKLOAD_REPLAY ADD_FILTER fname gt user_ichan Replaying a Database Workload 11 21 Replaying a Database Workload Using APIs fattribute gt USER fvalue gt ICHAN END In this example the ADD_FILTER procedure adds a filter named user_ichan which can be used to filter out all sessions belonging to the user name ICHAN The ADD_FILTER procedure in this example uses the following parameters The fname required parameter specifies the name of the filter that will be added a The fattribute required parameter specifies the attribute on which the filter will be applied Valid values include PROGRAM MODULE ACTION SERVICE USER and CONNECTION_STRING You must specify a valid captured connection string that will be used during replay as the CONNECTION_STRING attribute a The fvalue required parameter specifies the value for the corresponding attribute on which the filter will be applied It is possible to use wildcards such as with some of the attributes such as modules and actions Once all workload replay filters are added you can create a replay filter set that can be used when replaying the workload Deleting Workload Replay Filters To delete workload replay filters use the DELETE_FILTER procedur
87. Replay is to capture the production workload For more information about how capturing a database workload fits within the Database Replay architecture see Workload Capture on page 8 2 This chapter contains the following sections a Prerequisites for Capturing a Database Workload a Workload Capture Options a Workload Capture Restrictions Enabling and Disabling the Workload Capture Feature a Capturing a Database Workload Using Enterprise Manager a Monitoring Workload Capture Using Enterprise Manager Capturing a Database Workload Using APIs a Monitoring Workload Capture Using Views Prerequisites for Capturing a Database Workload Before starting a workload capture you should have a strategy in place to restore the database on the test system Before a workload can be replayed the logical state of the application data on the replay system should be similar to that of the capture system when replay begins To accomplish this consider using one of the following methods a Recovery Manager RMAN DUPLICATE command Snapshot standby a Data Pump Import and Export This will allow you to restore the database on the replay system to the application state as of the workload capture start time See Also a Oracle Database Backup and Recovery User s Guide for information about duplicating a database using RMAN a Oracle Data Guard Concepts and Administration for information about managing snapshot standby databases
88. Summary section which contains information about the captured workload in the selected directory Preprocess Captured Workload Cancel Preprocess Workload Directory Select a directory object that contains a captured workload TIP If the capture was done on a cluster database and a shared capture directory was not used copy the contents of the capture directories from all database instances into a single directory and then select the directory Directory Object CAPTURE 1 i Create Directory Object Y Capture Summary Name CAPTURE x112 Captured Data Size MB 0 04 20100726181024 Duration hh mm ss 00 08 09 Status Completed Start Time Jul 26 2010 6 12 45 PM PDT Directory Object CAPTURE1 End Time Jul 26 2010 6 20 54 PM PDT Database Name X112 Stat SCN 652040 Capture Database Version 11 2 0 2 0 End SCN 682254 DBID 2506747715 Preprocessed Database Version 11 2 0 2 0 Capture Error Code None SQL Tuning Set Name CAPTURE_x112_20100726_c_161852 Capture Error Message None Capture Details To view additional details about the captured workload expand Capture Details The expanded Capture Details section displays the workload profile and details for the captured workload 4 Click Preprocess Workload The Preprocess Captured Workload Database Version page appears 10 2 Oracle Database Real Application Testing User s Guide Preprocessing a Database Workload Using Enterprise Manager Preproce
89. UTIONS views display information about task executions SQL Performance Analyzer creates at 6 26 Oracle Database Real Application Testing User s Guide Comparing SQL Trials Using APIs least three executions to analyze the SQL performance impact caused by a database change on a SQL workload The first execution collects a pre change version of the performance data The second execution collects a post change version of the performance data The third execution performs the comparison analysis The DBA_ADVISOR_FINDINGS and USER_ADVISOR_FINDINGS views display the SQL Performance Analyzer findings SQL Performance Analyzer generates the following types of findings Problems such as performance regression Symptoms such as when the structure of an execution plan has changed Errors such as nonexistence of an object or view Informative messages such as when the structure of an execution plan in the pre change version is different than the one stored in the SQL tuning set a The DBA_ADVISOR_SQLPLANS and USER_ADVISOR_SQLPLANS views display a list of all execution plans a The DBA_ADVISOR_SQLSTATS and USER_ADVISOR_SQLSTATS views display a list of all SQL compilations and execution statistics a The VSADVISOR_PROGRESS view displays the operation progress of SQL Performanc
90. _ REPLAY COMPARE PERIOD_REPORT replay_idl gt 12 replay_id2 gt 17 format gt DBMS WORKLOAD CAPTURE TYPE_HTML result gt report_bind END In this example the COMPARE_PERIOD_REPORT procedure generates a replay compare period report in HTML format that compares a workload replay with a replay ID of 12 with another replay with an ID of 17 The COMPARE_PERIOD_REPORT procedure in this example uses the following parameters The replay_id1 parameter specifies the numerical identifier of the workload replay after change for which the reported will be generated This parameter is required The replay_id2 parameter specifies the numerical identifier of the workload replay before change for which the reported will be generated If unspecified the comparison will be performed with the workload capture a The format parameter specifies the report format Valid values include DBMS_ WORKLOAD_CAPTURE TYPE_HTML for HTML and DBMS_WORKLOAD CAPTURE TYPE_XML for XML This parameter is required The result parameter specifies the output of the report For information about how to interpret the replay compare period report see Reviewing Replay Compare Period Reports on page 12 9 See Also a Oracle Database PL SQL Packages and Types Reference for information about the DBMS_WORKLOAD_REPLAY package Generating SQL Performance Analyzer Reports Using APIs
91. a This page contains the following sections SQL Tuning Set This section summarizes information about the SQL tuning set including its name owner description and the number of SQL statements it contains a SQL Trials Creating an Analysis Task 3 11 Creating an Analysis Task Using Enterprise Manager This section includes a table that lists the SQL trials used in the SQL Performance Analyzer task SQL Trial Comparisons This section contains a table that lists the results of the SQL trial comparisons 9 Click the icon in the Comparison Report column The SQL Performance Analyzer Task Result page appears 10 Review the results of the performance analysis as described in Reviewing the SQL Performance Analyzer Report Using Oracle Enterprise Manager on page 6 3 Any SQL performance improvement with the Exadata simulation between the first and second trials is captured in the report In general you can expect a greater impact if the SQL workload contains queries that scan a large number of rows or a small subset of table columns Conversely a SQL workload that queries indexed tables or tables with fewer rows will result in a lesser impact from the Exadata simulation Using the Guided Workflow The guided workflow enables you to test the performance effect of any types of system changes on a SQL workload as listed in SQL Performance Analyzer on page 1 1 Note To create an analysis task to test database i
92. a Oracle Real Application Clusters Oracle RAC configuration workload capture is performed for the entire database To enable a clean state before starting to capture the workload all the instances need to be restarted To restart all instances in a Oracle RAC configuration before workload capture 1 Shut down all the instances 2 Restart one of the instances 3 Start workload capture 4 Restart the rest of the instances 9 2 Oracle Database Real Application Testing User s Guide Workload Capture Restrictions See Also a Oracle Database Administrator s Guide for information about restricting access to an instance at startup Using Filters with Workload Capture By default all user sessions are recorded during workload capture You can use workload filters to specify which user sessions to include in or exclude from the workload during workload capture There are two types of workload filters inclusion filters and exclusion filters You can use either inclusion filters or exclusion filters in a workload capture but not both Inclusion filters enable you to specify user sessions that will be captured in the workload This is useful if you want to capture only a subset of the database workload Exclusion filters enable you to specify user sessions that will not be captured in the workload This is useful if you want to filter out session types that do not need to captured in the workload such as those that monitor the infr
93. abase Real Application Testing User s Guide Comparing SQL Trials Using APIs db_version gt DBMS _SQLTUNE STS_STGTAB_11_1 VERSION END Use the db_version parameter to specify the appropriate database version to where the SQL tuning set will be exported and tuned In this example the staging table will be created with a format so that it can be exported to a system running Oracle Database 11g Release 1 where it will later be tuned using SQL Tuning Advisor For other database versions see Oracle Database PL SQL Packages and Types Reference for that release Export the SQL tuning set into the staging table BEGIN DBMS_SQLTUNE PACK_STGTAB_SQLSET sqlset_name gt SUB_STS1 sqlset_owner gt JOHNDOE staging_table_name gt STG_TAB1 staging_schema_owner gt JOHNDOE db_version gt DBMS_SQLTUNE STS_STGTAB_11_1_ VERSION END Move the staging table to the remote database where the SQL workload was executed using the mechanism of choice such as Oracle Data Pump or database link On the remote database import the SQL tuning set from the staging table BEGIN DBMS_SQLTUNE UNPACK_STGTAB_SQLSET sqlset_name gt SUB_STS1 staging_table_name gt STG_TAB1 replace gt TRUE END Tune the regressed SQL statements in the SQL tuning set by running SQL Tuning Advisor BEGIN sts_name SUB_STS1 sts_owner JOHNDOE tune_task_name TUNE_TASK1 tname DBMS_SQLTUNE CREATE_TUN
94. ad a Direct path load of data from external files using utilities such as SQL Loader a Non PL SQL based Advanced Queuing AQ a Flashback queries a Oracle Call Interface OCI based object navigations a NonSQL based object access a Distributed transactions any distributed transactions that are captured will be replayed as local transactions Capturing a Database Workload 9 3 Enabling and Disabling the Workload Capture Feature Enabling and Disabling the Workload Capture Feature Oracle Database 10 Release 2 supports using Database Replay to capture a database workload that can be used to test database upgrades to Oracle Database 11g and subsequent releases To use this feature it must be enabled on the capture system running Oracle Database 10g Release 2 before a workload can be captured By default the workload capture feature is not enabled in Oracle Database 10g Release 2 10 2 You can enable or disable this feature by specifying the PRE_11G_ENABLE_CAPTURI initialization parameter Ea Note Itis only necessary to enable the workload capture feature if you are capturing a database workload on a system running Oracle Database 10g Release 2 If you are capturing a database workload on a system running Oracle Database 11g Release 1 or a later release it is not necessary to enable the workload capture feature because it is enabled by default Furthermore the PRE_11G_ENABLE_CAPTURE initialization paramet
95. ad capturing 2 3 executing 2 5 2 7 transporting 2 4 system change making 5 1 task creating 7 3 7 10 usage 1 1 using 2 1 Index 2 workflow 2 1 Exadata simulation 3 9 guided 3 12 optimizer statistics 3 6 parameter change 3 3 SQL plan baselines creating 6 26 SQL statements regressed 1 1 2 8 6 8 6 22 6 24 7 3 7 11 7 15 SQL Trace about 7 3 enabling 7 2 7 3 trace level 7 4 SQL trace files about 7 3 moving 7 3 7 4 SQL trials about 2 5 2 6 building post upgrade version 7 3 7 6 7 11 pre upgrade version 7 3 7 9 7 11 7 14 comparing 6 2 SQL tuning set about 2 3 building 7 4 comparing 6 17 constructing 7 3 converting 7 3 7 9 U upgrade environment 7 2 7 10 W Workload Analyzer about 10 5 running 10 5
96. age cccccccccsee ee ceeeeteeeeeees 4 2 Creating a Pre Change SQL Trial Using APIS ccccceeeeesceeeeseseececssensnesesesesessneseseenes 4 4 Creating a Post Change SQL Trial Creating a Post Change SQL Trial Using Oracle Enterprise Managet 0 0 0ccceeeeees 5 2 Creating a Post Change SQL Trial Using APIs 0 ccccccseccccceeeecscecseeesescecesenseseesecesessneseeeeenes 5 3 Comparing SQL Trials Comparing SQL Trials Using Oracle Enterprise Manager 0ccccccsecceeeeeesceeeesneneseeees 6 2 Analyzing SQL Performance Using Oracle Enterprise Managet cccsecssesesescseseteseeeseees 6 2 Reviewing the SQL Performance Analyzer Report Using Oracle Enterprise Managet 6 3 Tuning Regressed SQL Statements Using Oracle Enterprise Manager ccsceeceeeteeeeees 6 8 Comparing SQL Trials Using APIS cece ceceeeeeeeeeeeesceeecesesseseeneseseseseneseseseseseneseseseeenes 6 10 Analyzing SQL Performance Using APIS ccccessssseseesesssssssenesessssssesesssssesesesssssesessiees 6 10 Reviewing the SQL Performance Analyzer Report Using APIs cccccssesssesesecseneneseeees 6 12 Comparing SQL Tuning Sets Using APIS cccesssssseesscseseesseesecseeeeessesesenseecesseseesesesseseneeeses 6 17 Tuning Regressed SQL Statements Using APIS cccccssessssssesesseseneescecesesssnenensneseseeneneseeeees 6 22 Tuning Regressed SQL Statements From a Remote SQL Trial Using APIs c cesses 6 24
97. age 11 5 After all replay clients are ready to start click Next The Replay Workload Wait for Client Connections page appears Replaying a Database Workload 11 11 Replaying a Database Workload Using Enterprise Manager Replay Workload Wait for Client Connections Database x090422 Cancel Back Step 4 of 5 Next Capture Name CAPTURE x090422 20090501115751 Logged InAs IMMCHAN After all the Replay Clients have connected proceed to the next step to continue the replay setup The database is waiting for connections from Replay Clients A This operation may take some time to complete If you close this browser window or navigate to a different page your place in the replay process will not be saved Client Connections No items found 14 Start the replay clients For information about starting replay clients see Setting Up Replay Clients on page 11 5 As replay clients are started the replay client connections will be displayed under Client Connections When all replay clients have connected click Next The Replay Workload Review page appears Replay Workload Review Logged In As IMMCHAN Back Step 5 of 5 Workload CAPTURE x112 20100806164334 will be replayed on database x112 Database x112 Capture Name CAPTURE x112 20100806164334 Replay Name REPLAY x112 20100806173137 Directory Object CAPTURE2 Capture SQL Tuning Set Yes Connected Replay Clients 1
98. aining statistics for a representative set of SQL statements that you want to use with SQL Performance Analyzer You can then copy the SQL trace files to the SQL Performance Analyzer system Once the SQL workload is captured in the SQL trace files disable SQL Trace on the production system See Also a Oracle Database Performance Tuning Guide for additional considerations when using SQL Trace such as setting initialization parameters to manage SQL trace files a Oracle Database PL SQL Packages and Types Reference for information about the DBMS_MONITOR package Creating a Mapping Table To convert the user and object identifier numbers stored in the SQL trace files to their respective names you need to provide a table that specifies each mapping The SQL Performance Analyzer system will read this mapping table when converting the trace files into a SQL tuning set To create a mapping table run the following SQL statements on the production database CREATE TABLE mapping AS SELECT object_id id owner SUBSTR object_name 1 30 name FROM dba_objects WHERE object_type NOT IN CONSUMER GROUP EVALUATION CONTEXT FUNCTION INDEXTYPE JAVA CLASS JAVA DATA JAVA RESOURCE LIBRARY LOB OPERATOR PACKAGE PACKAGE BODY PROCEDURE QUEUE RESOURCE PLAN SYNONYM TRIGGER TYPE TYPE BODY UNION ALL SELECT user_id id username owner null name FROM dba_us
99. alue should correspond to the value of the execut ion_name parameter specified in Creating a Post Change SQL Trial Using APIs on page 5 3 when you executed the SQL workload after the system change If the caller does not specify the executions then by default SQL Performance Analyzer will always compare the last two task executions 6 10 Oracle Database Real Application Testing User s Guide Comparing SQL Trials Using APIs Set the comparison_metric parameter to specify an expression of execution statistics to use in the performance impact analysis Possible values include the following metrics or any combination of them elapsed_time default cpu_time buffer_gets disk_reads direct_writes optimizer_cost and io_interconnect_bytes For other possible parameters that you can set for comparison see the description of the DBMS_SQLPA package in Oracle Database PL SQL Packages and Types Reference The following example illustrates a function call EXEC DBMS_SQLPA EXECUTE_ANALYSIS_TASK task_name gt my_spa_task execution_type gt COMPARE PERFORMANCE execution_name gt my_exec_compare execution_params gt dbms_advisor arglist comparison_metric buffer_gets Call the REPORT_ANALYSIS_TASK function using the following parameters Set the task_name parameter to the name of the SQL Performance Analyzer task Set the execution_name parameter to the name of the execution to use This value
100. and Oracle Database 10g Release 1 SQL Tuning Set This section summarizes information about the SQL tuning set including its name owner description and the number of SQL statements it contains a SQL Trials This section includes a table that lists the SQL trials used in the SQL Performance Analyzer task a SQL Trial Comparisons This section contains a table that lists the results of the SQL trial comparisons 11 Click the icon in the Comparison Report column The SQL Performance Analyzer Task Result page appears 12 Review the results of the performance analysis as described in Reviewing the SQL Performance Analyzer Report Using Oracle Enterprise Manager on page 6 3 If regressed SQL statements are found following the database upgrade tune them as described in Tuning Regressed SQL Statements After Testing a Database Upgrade on page 7 15 Testing Database Upgrades from Oracle9i Database and Oracle Database 10g Release 1 Using APIs After creating a SQL Performance Analyzer task on the SQL Performance Analyzer system you can use APIs to build the pre upgrade SQL trial from the execution plans and run time statistics in the SQL tuning set To do so call the EXECUTE_ANALYSIS TASK procedure using the following parameters a Set the task_name parameter to the name of the SQL Performance Analyzer task that you want to execute a Set the execution_type parameter to CONVERT SQLSET to direct SQL Performance A
101. arting a Workload Replay Before starting a workload replay you must first Preprocess the captured workload as described in Preprocessing a Database Workload Using APIs on page 10 4 a Initialize the replay data as described in Initializing Replay Data on page 11 19 Specify the replay options as described in Setting Workload Replay Options on page 11 20 Start the replay clients as described in Starting Replay Clients on page 11 6 11 24 Oracle Database Real Application Testing User s Guide Replaying a Database Workload Using APIs Note Once a workload replay is started new replay clients will not be able to connect to the database Only replay clients that were started before the START_REPLAY procedure is executed will be used to replay the captured workload To start a workload replay use the START_REPLAY procedure BEGIN DBMS_WORKLOAD_REPLAY START_REPLAY END Pausing a Workload Replay To pause a workload replay that is in progress use the PAUSE_REPLAY procedure BEGIN DBMS_WORKLOAD_REPLAY PAUSE_REPLAY END Pausing a workload replay will halt all subsequent user calls issued by the replay clients until the workload replay is either resumed or cancelled User calls that are already in progress will be allowed to complete This option enables you to temporarily stop the replay to perform a change and observe its impact for the remainder of the replay
102. as the pre change SQL trial Once built the post change SQL trial represents a new set of performance data that can be used to compare to the pre change version The results are stored in a new or post change SQL trial See Also a Chapter 5 Creating a Post Change SQL Trial for information about how to measure the post change performance Comparing Performance Measurements SQL Performance Analyzer compares the performance of SQL statements before and after the change and produces a report identifying any changes in execution plans or performance of the SQL statements SQL Performance Analyzer measures the impact of system changes both on the overall execution time of the SQL workload and on the response time of every individual SQL statement in the workload By default SQL Performance Analyzer uses elapsed time as a metric for comparison Alternatively you can choose the metric for comparison from a variety of available SQL run time statistics including a CPU time a User I O time a Buffer gets a Physical 1 O a Optimizer cost a I O interconnect bytes a Any combination of these metrics in the form of an expression If you chose to generate explain plans only in the SQL trials then SQL Performance Analyzer will use the optimizer cost stored in the SQL execution plans Once the comparison is complete the resulting data is generated into a SQL Performance Analyzer report that compares the pre change and post change SQL per
103. ase using a database link SQL Performance Analyzer will establish a connection to the remote database using the database link execute the SQL statements on that database collect the execution plans and run time statistics for each SQL statement and store the results in a SQL trial on the local database that can be used for later analysis This method is useful in cases where you want to a Test a database upgrade a Execute the SQL workload on a system running another version of Oracle Database Store the results from the SOL Performance Analyzer analysis on a separate test system Perform testing on multiple systems with different hardware configurations a Use the newest features in SQL Performance Analyzer even if you are using an older version of Oracle Database on your production system Once the SQL workload is executed the resulting execution plans and run time statistics are stored in a SQL trial You can also build a SQL trial using the execution statistics and plan stored in a SQL tuning set While this method is only supported for APIs it may be useful in cases where you have another method to run your workload such as Database Replay or another application testing tool and you do not need SQL Performance Analyzer to drive the workload on the test system In such cases if you capture a SQL tuning set during your test runs you can build SQL trials from these SQL tuning sets using SQL Performance Analyzer to view a mor
104. ase 1 and newer releases Note To use the workload capture feature on a system running Oracle9i Database or an earlier version of Oracle Database 10 Release 2 contact Oracle Support for more information Analyzing the effect of system changes using Database Replay involves the following steps as illustrated in Figure 8 1 Introduction to Database Replay 8 1 Workload Capture Figure 8 1 Database Replay Workflow Production Test Client Client Client em va Client Workload 1 On the production system capture the workload into capture files as described in Workload Capture on page 8 2 2 Copy the capture files to the test system and preprocess them as described in Workload Preprocessing on page 8 3 3 On the test system replay the preprocessed files as described in Workload Replay on page 8 3 4 Using the reports generated by Database Replay perform detailed analysis of both the workload capture and workload replay as described in Analysis and Reporting on page 8 3 Workload Capture The first step in using Database Replay is to capture the production workload Capturing a workload involves recording all requests made by external clients to Oracle Database When workload capture is enabled all external client requests directed to Oracle Database are tracked and stored in binary files called capture files on the file system You can specify the location where the captu
105. ason Oracle Enterprise Manager is unavailable you can create a pre change SQL trial using the DBMS_SQLPA PL SQL package Tip Before creating a pre change SQL trial you need to create a SQL Performance Analyzer task as described in Chapter 3 Creating an Analysis Task Creating a Pre Change SQL Trial Using Enterprise Manager This section describes how to collect the pre change SQL performance data using Oracle Enterprise Manager To create a pre change SQL trial using Enterprise Manager 1 On the Guided Workflow page click the Execute icon for the Create SQL Trial in Initial Environment step The Create SQL Trial page appears A summary of the selected SQL tuning set containing the SQL workload is displayed Create SQL Trial SQL Trials capture execution performance of the SQL Tuning Set under a given optimizer environment SQL Performance Analyzer Task IMMCHAN SPA_GUIDED_WORKFLOW SQL Tuning Set IMMCHAN STS_CURSOR_CACHE SQL Trial Name SQL_TRIAL_1241213421833 SQL Trial Description Creation Method Execute SQLs Locally v Per SQL Time Limit 5 minutes Schedule Time Zone Pacific Pago_Pago Immediately O Later Date May 1 2009 exemple M Time 2_ 21 M 00 Oam Pm TIP Time limit is on elapsed time of test execution of SQL Cancel Submit Trial environment determines results The SQL Tuning Set remains constant under the SQL Performanc
106. astructure like Oracle Enterprise Manager EM or Statspack or other such processes that are already running on the test system For example if the system where the workload will be replayed is running EM replaying captured EM sessions on the system will result in duplication of workload In this case you may want to use exclusion filters to filter out EM sessions Setting Up the Capture Directory Determine the location and set up a directory where the captured workload will be stored Before starting the workload capture ensure that the directory is empty and has ample disk space to store the workload If the directory runs out of disk space during a workload capture the capture will stop To estimate the amount of disk space that is required you can run a test capture on your workload for a short duration such as a few minutes to extrapolate how much space you will need for a full capture To avoid potential performance issues you should also ensure that the target replay directory is mounted on a separate file system For Oracle RAC consider using a shared file system Alternatively you can set up one capture directory path that resolve to separate physical directories on each instance but you will need to collect the capture files created in each of these directories into a single directory before preprocessing the workload capture Workload Capture Restrictions The following types of client requests are not captured in a worklo
107. at contains the captured workload to be preprocessed Tip After preprocessing a captured workload you can replay it on the test system as described in Chapter 11 Replaying a Database Workload 10 4 Oracle Database Real Application Testing User s Guide Preprocessing a Database Workload Using APIs See Also a Oracle Database PL SQL Packages and Types Reference for information about the DBMS_WORKLOAD_REPLAY package Running the Workload Analyzer Command Line Interface The Workload Analyzer is a Java program that analyzes a workload capture directory and identifies parts of a captured workload that may not replay accurately due to insufficient data errors that occurred during workload capture or usage features that are not supported by Database Replay The results of the workload analysis are saved to an HTML report named wcr_cap_analysis html located in the capture directory that is being analyzed If an error can be prevented the workload analysis report displays available preventive actions that can be implemented before replay If an error cannot be corrected the workload analysis report provides a description of the error so it can be accounted for during replay Running Workload Analyzer is the default option and is strongly recommended Note If you are preprocessing a workload capture using Oracle Enterprise Manager then you do not need to run Workload Analyzer in the command line interface Oracle Ente
108. atements captured in the SQL trace files along with their relevant execution context and statistics On the SQL Performance Analyzer system use SQL Performance Analyzer to create a SQL Performance Analyzer task and convert the contents in the SQL tuning set into a pre upgrade SQL trial that will be used as a baseline for comparison then remotely test execute the SOL statements on the test system over a database link to build a post upgrade SQL trial as described in Testing Database Upgrades from Oracle9i Database and Oracle Database 10g Release 1 on page 7 6 Compare SQL performance and fix regressed SQL SQL Performance Analyzer compares the performance of SQL statements read from the SQL tuning set during the pre upgrade SQL trial to those captured from the remote test execution during the post upgrade SQL trial A report is produced to identify any changes in execution plans or performance of the SQL statements If the report reveals any regressed SQL statements you can make further changes to fix the regressed SQL as described in Tuning Regressed SQL Statements After Testing a Database Upgrade on page 7 15 Repeat the process of executing the SQL tuning set and comparing its performance to a previous execution to test any changes made until you are satisfied with the outcome of the analysis Enabling SQL Trace on the Production System Oracle9i uses the SQL Trace facility to collect performance data on individual SQL statements
109. atements chosen the following columns are included a SQLID This column indicates the ID of the SQL statement Net Impact on Workload This column indicates the impact of the system change relative to the performance of the SQL workload Elapsed Time This column indicates the total time in seconds of the SQL statement execution a Net Impact on SQL This column indicates the local impact of the change on the performance of a particular SQL statement NewPlan This column indicates whether the SQL execution plan changed 2 To view details about a particular SQL statement click the SQL ID link for the SQL statement that you are interested in The SQL Details page appears You can use this page to access the SQL text and obtain low level details about the SQL statement such as its execution statistics and execution plan About SQL Performance Analyzer Active Reports SQL Performance Analyzer active reports are HTML files that display all reporting data using a Web hosted interactive user interface Similar to the SQL Performance Analyzer reports available in Oracle Enterprise Manager active reports include information about the top SQL statements from each category such as improved regressed and changed plans with pre change and post change statistics explain plans and task summary Comparing SQL Trials 6 7 Comparing SQL Trials Using Oracle Enterprise Manager SQL Performance Analyzer active re
110. atements through SQL Performance Analyzer This can be done on the database running SPA Performance Analyzer or on a remote database Unlike the EXPLAIN PLAN statement SQL trials using the explain plan method take bind values into account and generate the actual execution plan Convert SQL tuning set This method converts the execution statistics and plans stored in a SQL tuning set This is only supported for APIs The test execute method runs each of the SQL statements contained in the workload to completion During execution SOL Performance Analyzer generates execution plans and computes execution statistics for each SQL statement in the workload Each SQL statement in the SQL tuning set is executed separately from other SQL statements without preserving their initial order of execution or concurrency This is done at least twice for each SQL statement for as many times as possible until the execution times out up to a maximum of 10 times The first execution is used to warm the buffer cache All subsequent executions are then used to calculate the run time execution statistics for the SQL statement based on their averages The actual number of times that the SQL statement is executed depends on how long it takes to execute the SQL statement Long running SQL statement will only be executed a second time and the execution statistics from this execution will be used Other faster running SQL statements are executed multiple times an
111. ay bar is shorter than the Capture bar the replay environment is processing the workload faster than the capture environment Replay 0 2 4 6 8 10 12 Elapsed Time Minutes Network Time hh mm ss 00 00 01 Think Time hh mm ss 00 00 00 The divergence table gives information about both the data and error discrepancies between the replay and capture environments which can be used as a measure of the replay quality Clients 1 Clients Finished 0 Divergence Number of Percentage of View Workload Replay Report Calls Total Calls Error Divergence Session Failures Seen During Replay 0 0 00 Errors No Longer Seen During Replay 0 0 00 Errors Mutated During Replay 0 0 00 New Errors Seen During Replay 0 0 00 Data Divergence DMLs with Different Number of Rows Modified 0 0 00 SELECTs with Different Number of Rows Fetched 0 0 00 Detailed Comparison Once the workload replay is completed you can assess various types of information about the replay using this page as described in Viewing a Completed Workload Replay on page 11 14 To stop the workload replay manually click Stop Replay To return to the Database Replay page click OK Viewing a Completed Workload Replay This section describes how to view a completed workload replay using Enterprise Manager To view a completed workload replay 1 On the Software and Support page under Real Application Testing click Database Replay The Database Replay page ap
112. base after the pre upgrade trial step is completed After the database is upgraded the post upgrade trial can be executed After the task completes the Status field changes to Completed Under SQL Performance Analyzer Tasks select the task and click the link in the Name column The SQL Performance Analyzer Task page appears This page contains the following sections a SQL Tuning Set This section summarizes information about the SQL tuning set including its name owner description and the number of SQL statements it contains a SQL Trials This section includes a table that lists the SQL trials used in the SQL Performance Analyzer task SQL Trial Comparisons This section contains a table that lists the results of the SQL trial comparisons Click the icon in the Comparison Report column The SQL Performance Analyzer Task Result page appears Review the results of the performance analysis as described in Reviewing the SQL Performance Analyzer Report Using Oracle Enterprise Manager on page 6 3 If regressed SQL statements are found following the database upgrade tune them as described in Tuning Regressed SQL Statements After Testing a Database Upgrade on page 7 15 Testing Database Upgrades from Oracle Database 10g Release 2 and Newer Releases Using APIs After creating a SQL Performance Analyzer task on the SQL Performance Analyzer system you can use APIs to build the pre upgrade SQL trial by performing an explain plan o
113. base to the higher database version before the post upgrade trial is executed b In the Database Link field enter the global name of a public database link connecting to a user with the EXECUTE privilege for the DBMS_SQLPA package and the ADVISOR privilege on the post upgrade system In the Comparison Metric list select the comparison metric to use for the comparison analysis Elapsed Time CPU Time User I O Time Buffer Gets Physical I O Optimizer Cost I O Interconnect Bytes Optimizer Cost is the only comparison metric available if you generated execution plans only in the SQL trials Testing a Database Upgrade 7 13 Upgrading from Oracle Database 10g Release 2 and Newer Releases 10 11 12 13 To perform the comparison analysis by using more than one comparison metric perform separate comparison analyses by repeating this procedure with different metrics Under Schedule a Inthe Time Zone list select your time zone code b Select Immediately to start the task now or Later to schedule the task to start at a time specified using the Date and Time fields Click Submit The SQL Performance Analyzer page appears In the SQL Performance Analyzer Tasks section the status of this task is displayed To refresh the status icon click Refresh If you are using the same system to execute both the pre upgrade and post upgrade trials you will need to upgrade the data
114. be running Oracle9i or Oracle Database 10 Release 1 The test system which you are upgrading to should be running Oracle Database 10g Release 2 or a newer release The database version can be release 10 2 0 2 or higher If you are upgrading to Oracle Database 10g release 10 2 0 2 10 2 0 3 or 10 2 0 4 you will also need to install a one off patch before proceeding To ensure that the analysis made by SQL Performance Analyzer is accurate the test system should resemble the production system as closely as possible because the performance on both systems will be compared to each other Furthermore the hardware configurations on both systems should also be as similar as possible Next you will need to set up a separate SQL Performance Analyzer system running Oracle Database 11g Release 2 You will be using this system to build a SQL tuning set and to run SQL Performance Analyzer Neither your production data or schema need to be available on this system since the SQL tuning set will be built using statistics stored in the SQL trace files from the production system SQL Performance Analyzer tasks will be executed remotely on the test system to generate the execution plan and statistics for the SQL trial over a database link that you specify The database link must be a public database link that connects to a user with the EXECUTE privilege for the DBMS_SQLPA package and the ADVISOR privilege on the test system You should also drop any existing PLAN_T
115. captured SQL statements should include the following information a SQL text a Execution environment SQL binds which are bind values needed to execute a SQL statement and generate accurate execution statistics Parsing schema under which a SQL statement can be compiled Compilation environment including initialization parameters under which a SQL statement is executed a Number of times a SQL statement was executed Capturing a SQL workload has a negligible performance impact on your production system and should not affect throughput A SQL workload that contains more SQL statements will better represent the state of the application or database This will enable SQL Performance Analyzer to more accurately forecast the potential impact of system changes on the SQL workload Therefore you should capture as many SQL statements as possible Ideally you should capture all SQL statements that are either called by the application or are running on the database You can store captured SQL statements in a SQL tuning set and use it as an input source for SQL Performance Analyzer A SQL tuning set is a database object that includes one or more SQL statements along with their execution statistics and execution context SQL statements can be loaded into a SQL tuning set from different sources including the cursor cache Automatic Workload Repository AWR and existing SQL tuning sets Capturing a SQL workload using a SQL tuning set enables you
116. ccscesssseseseeteteneees 12 3 Generating Workload Replay Reports Using APIS ccccscsssssseseseescecesesssesnenseseseeneeseeeees 12 4 Reviewing Workload Replay Reports ccccccsssessssssssssesesesssessesesescsesssesescscssssseecscscsssnseecsees 12 5 Using Compare Period Reports ccccccceseseccscesesescscscsesesescscsesesesescscssseseececesessnsnecesesensnesesecenes 12 6 Generating Compare Period Reports Using Enterprise Manager cccccccesccstesessseeneteneees 12 6 Generating Compare Period Reports Using APIS cccccscsceseeseensteesesseneesceneesesesneneneneees 12 7 Reviewing Replay Compare Period Reports 0 ccccccssssesesesssssesesescsesssesesescseseseecsesessanseeesees 12 9 Index Audience Preface This preface contains the following topics a Audience a Documentation Accessibility a Related Documents a Conventions This document provides information about how to assure the integrity of database changes using Oracle Real Application Testing This document is intended for database administrators application designers and programmers who are responsible for performing real application testing on Oracle Database Documentation Accessibility Our goal is to make Oracle products services and supporting documentation accessible to all users including users that are disabled To that end our documentation includes features that make information available to users of assistive technology
117. ch SQL statement in the SQL tuning set by actually running the SQL statements locally on the test system a Select Execute SQLs Remotely The SQL trial generates both execution plans and statistics for each SQL statement in the SQL tuning set by actually running the SQL statements remotely on another test system over a public database link 4 2 Oracle Database Real Application Testing User s Guide Creating a Pre Change SQL Trial Using Enterprise Manager Select Generate Plans Locally The SQL trial invokes the optimizer to create execution plans locally on the test system after taking bind values and optimizer configuration into account without actually running the SQL statements a Select Generate Plans Remotely The SQL trial invokes the optimizer to create execution plans remotely on another test system after taking bind values and optimizer configuration into account over a public database link without actually running the SQL statements a Select Build From SOL Tuning Set The SQL trial copies the execution plans and statistics from the SQL tuning set directly into the trial For more information about the different methods see Measuring the Pre Change SQL Performance on page 2 5 In the Per SQL Time Limit list determine the time limit for SQL execution during the trial by performing one of the following actions a Select 5 minutes The execution will run each SQL statement in the SQL tuning set up to 5
118. contained in a workload that was captured or replayed Before running this report AWR data must have been previously exported from the captured or replayed workload To run this report under AWR Report select the workload capture or replay for which you want to generate an AWR report and click Run Report If AWR data is not previously exported from the captured or replayed workload you will be prompted to import the AWR data before continuing For more information about the AWR report see Oracle Database Performance Tuning Guide ASH The ASH report contains active session history ASH information for a specified duration of a workload that was captured or replayed Before running this report AWR data must have been previously exported from the captured or replayed workload To run this report under ASH Report select the workload capture or replay for which you want to generate an ASH report Specify the duration using the Start Date Start Time End Date and End Time fields You can also apply filters using the Filter field Once the duration and filters are specified click Run Report If AWR data is not previously exported from the captured or replayed workload you will be prompted to import the AWR data before continuing For more information about the ASH report see Oracle Database 2 Day Performance Tuning Guide The Report window opens while the report is being generated Once the report is generated you can save the report by cl
119. csssissssecsississsecscessessvseceetesseascortesaszecsensiosuensstetosbesestusscvbinstetbeneosstite 11 25 Resuming a Workload Replay cccccccceesesssssssssssessssssssssessssssssseesssssesesesssssseessssssseeseess 11 25 Cancelling a Workload Replayer neasi esn esses eetere Snee ei iesse ai raiant 11 25 Exporting AWR Data for Workload Replay sssssssssesessesssssisissessssssestesissesssesiestesenssesteseenne 11 25 Monitoring Workload Replay Using APIS sn sensseseseeseeseestsssestestesttssestestestisnesnenreseeseesneseenee 11 26 Retrieving Information About Diverged Calls 0 0 cccceseescssssssssesesesssssesescsessesesesesssesesescsens 11 26 Monitoring Workload Replay Using VieWS cc cccccsc cscs ce cssssseesesssssssesesessssesesessessesssees 11 26 vi 12 Analyzing Replayed Workload Using Workload Capture Reports 0 0 cccc cece cece eeeseecececeeseeeececesssseenesessseseneceseseseseneseseseeenes 12 1 Generating Workload Capture Reports Using Enterprise Manager cccccccesesesseseteeees 12 1 Generating Workload Capture Reports Using APIS ccccscsessseseecenereesesneneeseeceseseseanenenes 12 2 Reviewing Workload Capture Reports cccccsssessesssssssesesesssssseseescsesssesescscssssseecsescssensnessees 12 3 Using Workload Replay Reports cccccc cscs cc ceeseececscesseseececesssssseesecesessneseseseseseneseseseenes 12 3 Generating Workload Replay Reports Using Enterprise Manager c
120. ct existing execution plans in the future For more information see Creating SQL Plan Baselines Using APIs on page 6 26 7 16 Oracle Database Real Application Testing User s Guide Part Il Database Replay Database Replay enables you to replay a full production workload on a test system to assess the overall impact of system changes This part contains information about how to capture preprocess and replay a database workload using Database Replay as well as how to analyze the results of a replayed workload Part II contains the following chapters a Chapter 8 Introduction to Database Replay a Chapter 9 Capturing a Database Workload a Chapter 10 Preprocessing a Database Workload Chapter 11 Replaying a Database Workload a Chapter 12 Analyzing Replayed Workload 8 Introduction to Database Replay You can use Database Replay to capture a workload on the production system and replay it on a test system with the exact timing concurrency and transaction characteristics of the original workload This enables you to test the effects of a system change without affecting the production system Database Replay supports workload capture on a system running Oracle Database 10g Release 2 and newer releases In order to capture a workload on a system running Oracle Database 10g Release 2 the database version can be 10 2 0 4 or higher Workload replay is only supported on systems running Oracle Database 11g Rele
121. ctions may cause replay divergence when replayed ona system that has a different system time Resetting the system time will also minimize job scheduling inconsistencies between capture and replay Note When resetting the system time ensure that future Automatic Workload Repository AWR snapshots can still be created automatically as expected after the system time is reset Steps for Replaying a Database Workload Proper planning of the workload replay ensures that the replay will be accurate Replaying a database workload requires the following steps a Setting Up the Replay Directory Resolving References to External Systems a Remapping Connections Specifying Replay Options a Using Filters with Workload Replay a Setting Up Replay Clients Setting Up the Replay Directory The captured workload must have been preprocessed and copied to the replay system A directory object for the directory to which the preprocessed workload is copied must exist in the replay system Resolving References to External Systems A captured workload may contain references to external systems such as database links or external tables Typically you should reconfigure these external interactions to avoid impacting other production systems during replay External references that need to be resolved before replaying a workload include a Database links It is typically not desirable for the replay system to interact with other
122. ctive Workload Capture Stopping an Active Workload Capture Managing a Completed Workload Capture Monitoring an Active Workload Capture This section describes how to monitor an active workload capture using Enterprise Manager To monitor an active workload capture 1 On the Software and Support page under Real Application Testing click Database Replay The Database Replay page appears 2 Under Active Capture and Replay select the workload capture you want to monitor and click View The View Workload Capture page appears 9 10 Oracle Database Real Application Testing User s Guide Monitoring Workload Capture Using Enterprise Manager View Workload Capture CAP TURE x112 20100806164334 Page Refreshed Aug 6 2010 5 00 24 PM PDT Refresh 0K Status In Progress Stop Capture Y Summary Name CAPTURE x112 20100806164334 Captured Data Size MB 0 04 Directory Object CAPTURE2 Duration hh mm ss 00 10 30 2 Database Name X112 Start Time Aug 6 2010 4 49 54 PM PDT Capture Database Version 11 2 0 2 0 End Time n a DBID 2506747715 Start SCN 2119526 Capture Error Code None End SCN n a Capture Error Message None SQL Tuning Set Name CAPTURE_x112_2010080_c_3113294 Workload Profile Workload Filters View Workload Capture Report Average Active Sessions 2 0 E others 0 8 f a Fi T E Capture Active Sessions 4 49 5 00 5 10 5 20 5 30 5 40 Aug 6 2010 Comparison Total Capture Percentage
123. d Workload Review Logged In As IMMCHAN Cancel Back Step 3 of 3 Submit Workload CAPTURE x112 20100726181024 will be preprocessed on database x112 Job Name PREPROCESS X112 20100726183202 Database x112 Preprocessed Database Version 11 2 0 2 0 Directory Object CAPTURE1 Capture Name CAPTURE x112 20100726181024 Captured Data Size MB 0 04 Start Time Immediately Run Workload Analyzer Yes 7 Review the selected options for the preprocessing job To preprocess the captured workload click Submit To make changes click Back To cancel preprocessing without saving changes click Cancel Tip After preprocessing a captured workload you can replay it on the test system as described in Chapter 11 Replaying a Database Workload Preprocessing a Database Workload Using APIs This section describes how to preprocess a captured workload using the DBMS_ WORKLOAD_REPLAY package You can also use Oracle Enterprise Manager to preprocess a captured workload as described in Preprocessing a Database Workload Using Enterprise Manager on page 10 1 To preprocess a captured workload use the PROCESS_CAPTURE procedure BEGIN DBMS_WORKLOAD_REPLAY PROCESS_CAPTURE capture_dir gt dec06 END In this example the captured workload stored in the dec06 directory will be preprocessed The PROCESS_CAPTURE procedure in this example uses the capture_dir required parameter which specifies the directory th
124. d their execution statistics are averaged over these executions statistics from the first execution are not used in the calculation By averaging statistics over multiple executions SQL Performance Analyzer can calculate more accurate execution statistics for each SQL statement To avoid a potential impact to the database DDLs are not supported By default only the query portion of DMLs is executed Using APIs you can execute the full DML by Introduction to SQL Performance Analyzer 2 5 Measuring the Pre Change SQL Performance using the EXECUTE_FULLDML task parameter Parallel DMLs are not supported and the query portion is not executed unless the parallel hints are removed Depending on its size executing a SQL workload can be time and resource intensive With the explain plan method you can choose to generate execution plans only without collecting execution statistics This technique shortens the time to run the trial and lessens the effect on system resources but a comprehensive performance analysis is not possible because only the execution plans will be available during the analysis However unlike generating a plan with the EXPLAIN PLAN command SQL Performance Analyzer provides bind values to the optimizer when generating execution plans which provides a more reliable prediction of what the plan will be when the SQL statement is executed In both cases you can execute the SQL workload remotely on a separate datab
125. database workload using the DBMS_WORKLOAD_CAPTURE package involves Defining Workload Capture Filters Starting a Workload Capture Stopping a Workload Capture Exporting AWR Data for Workload Capture See Also a Oracle Database PL SQL Packages and Types Reference for information about the DBMS_WORKLOAD_CAPTURE package Capturing a Database Workload 9 13 Capturing a Database Workload Using APIs Defining Workload Capture Filters This section describes how to add and remove workload capture filters For information about using workload filters with workload capture see Using Filters with Workload Capture on page 9 3 To add filters to a workload capture use the ADD_FILTER procedure BEGIN DBMS_WORKLOAD_CAPTURE ADD_FILTER fname gt user_ichan fattribute gt USER fvalue gt ICHAN END In this example the ADD_FILTER procedure adds a filter named user_ichan which can be used to filter out all sessions belonging to the user name ICHAN The ADD_FILTER procedure in this example uses the following parameters The fname required parameter specifies the name of the filter that will be added a The fattribute required parameter specifies the attribute on which the filter will be applied Valid values include PROGRAM MODULE ACTION SERVICE INSTANCE_NUMBER and USER a The fvalue required parameter specifies the value for
126. disabled The default value is TRUE The min_delay parameter defines the lower bound value of call delay in minutes The replay timeout action is only activated when the delay is over this value The default value is 10 a The max_delay parameter defines the upper bound value of call delay in minutes The replay timeout action is activated and issues an error when the delay is over this value The default value is 120 The delay_factor parameter defines a factor for the call delays that are between the values of min_delay and max_delay The replay timeout action issues an error when the current replay elapsed time is higher than the multiplication of the capture elapsed time and this value The default value is 8 To retrieve the replay timeout action setting use the GET_REPLAY_TIMEOUT procedure DECLARE enabled BOOLEAN min_delay NUMBER max_delay NUMBER delay_factor NUMBER BEGIN DBMS_WORKLOAD_REPLAY GET_REPLAY_ TIMEOUT enabled min_delay max_delay delay_factor END The GET_REPLAY_TIMEOUT procedure in this example returns the following parameters a The enabled parameter returns whether the replay timeout action is enabled or disabled a The min_delay parameter returns the lower bound value of call delay in minutes a The max_delay parameter returns the upper bound value of call delay in minutes The delay_factor parameter returns the delay factor St
127. e BEGIN DBMS_WORKLOAD_REPLAY DELETE FILTER fname gt user_ichan END In this example the DELETE_FILTER procedure removes the filter named user_ichan The DELETE_FILTER procedure in this example uses the fname required parameter which specifies the name of the filter to be removed Creating a Replay Filter Set After the workload replay filters are added you can create a set of replay filters to use with workload replay When creating a replay filter set all workload replay filters that were added since the previous replay filter set was created will be used To create a replay filter set use the CREATE_FILTER_SET procedure BEGIN DBMS_WORKLOAD_REPLAY CREATE_FILTER_SET replay_dir gt apr09 filter_set gt replayfilters default_action gt INCLUDE END In this example the CREATE_FILTER_SET procedure creates a replay filter set named replayfilters which will replay all captured calls for the replay stored in the apr09 directory except for the part of the workload defined by the replay filters The CREATE_FILTER_SET procedure in this example uses the following parameters a The replay_dir parameter specifies the directory where the replay to be filtered is stored 11 22 Oracle Database Real Application Testing User s Guide Replaying a Database Workload Using APIs The f
128. e 11 25 COMPARE_PERIOD_REPORT procedure 12 8 COMPARE_SQLSET_REPORT procedure 12 9 CREATE_FILTER_SET procedure 11 22 DELETE_FILTER procedure 11 22 EXPORT_AWR procedure 11 25 GET_DIVERGING_STATEMENT function 11 26 GET_REPLAY_INFO procedure 12 4 INITIALIZE_REPLAY procedure 11 19 PAUSE_REPLAY procedure 11 25 PREPARE_REPLAY procedure 11 20 PROCESS_CAPTURE procedure 10 4 REMAP_CONNECTION procedure 11 19 Index 1 REPORT function 12 4 RESUME_REPLAY procedure 11 25 SET_REPLAY_TIMEOUT procedure 11 23 START_REPLAY procedure 11 25 USE_FILTER_SET procedure 11 23 mapping table about 7 4 creating 7 3 7 4 moving 7 3 7 4 R Real Application Testing about 1 1 components 1 1 S SQL Performance Analyzer about 1 1 comparing performance 6 10 7 3 7 11 creating a task 3 1 3 13 executing the SQL workload 4 2 4 4 executing the SQL workload after a change 5 2 5 3 initial environment establishing 4 1 input source 7 1 making a change 5 1 methodology 2 1 monitoring 6 26 performance data collecting post change version 5 1 collecting pre change version 4 1 comparing 6 1 remote test execution 7 6 7 11 reporting 2 7 setting up the test system 2 4 SQL Performance Analyzer report active reports 6 7 general information 6 5 6 12 global statistics 6 5 global statistics details 6 7 result details 6 15 result summary 6 13 reviewing 6 3 6 12 SQL tuning set selecting 2 5 3 1 SQL worklo
129. e Analyzer Use this view to monitor how many SQL statements have completed or are awaiting execution in a SQL trial The SOFAR column indicates the number of SQL statements processed so far and the TOTAL WORK column shows the total number of SQL statements to be processed by the task execution You must have the SELECT_CATALOG_ROLE role to access the DBA views See Also Oracle Database Reference for information about the DBA_ ADVISOR_TASKS DBA_ADVISOR_EXECUTIONS and DBA_ ADVISOR_SQLPLANS views Comparing SQL Trials 6 27 Comparing SQL Trials Using APIs 6 28 Oracle Database Real Application Testing User s Guide T Testing a Database Upgrade SQL Performance Analyzer supports testing database upgrades from Oracle9i and later releases to Oracle Database 10g Release 2 or newer releases The methodology used to test a database upgrade from Oracle9i Database and Oracle Database 10g Release 1 is slightly different from the one used to test a database upgrade from Oracle Database 10g Release 2 and later releases so both methodologies are described here This chapter describes how to use SQL Performance Analyzer in a database upgrade and contains the following sections Upgrading from Oracle9i Database and Oracle Database 10g Release 1 Upgrading from Oracle Database 10g Release 2 and Newer Releases a Tuning Regressed SQL Statements After Testing a Database Up
130. e Analyzer Task and its SQL is executed in isolation to create each SQL Trial Performance differences between trials are thus attributed to environmental differences between trials Environmental changes affecting SQL optimization and performance may need to be made manually prior to execution of the Trial These could include changing initialization parameters gathering or setting optimizer statistics and creating indexes The Creation Method determines how the SQL Trial is created and what contents are generated as follows e Executing SQLs generates both plans and statistics by actually running the SQL statements e Generating plans invokes the optimizer to create execution plans only without running the SQL statements e Remote execution and plan generation are done over a public database link on the remote system e Building from the SQL Tuning Set simply copies the plans and statistics from the Tuning Set directly into the Trial NOTE Be sure trial environment has been established prior to submitting Trial environment established 2 Inthe SQL Trial Name field enter the name of the SQL trial 3 In the SQL Trial Description field enter a description of the SQL trial 4 Inthe Creation Method list determine how the SQL trial is created and what contents are generated by performing one of the following actions a Select Execute SQLs Locally The SQL trial generates both execution plans and statistics for ea
131. e comprehensive analysis report Unlike a standard SQL Performance Analyzer report which has only one execution plan in each trial and one set of execution statistics generated by executing the SQL statement with one set of binds you can generate a report that compares SQL trials built from SQL tuning sets that show all execution plans from both trials with potentially many different sets of binds across multiple executions See Also a Chapter 4 Creating a Pre Change SQL Trial for information about how to measure the pre change performance Chapter 7 Testing a Database Upgrade for information about executing a SQL workload on a remote system to test a database upgrade 2 6 Oracle Database Real Application Testing User s Guide Comparing Performance Measurements Making a System Change Make the change whose effect on SQL performance you intend to measure SQL Performance Analyzer can analyze the effect of many types of system changes For example you can test a database upgrade new index creation initialization parameter changes or optimizer statistics refresh If you are running SQL Performance Analyzer on the production system then consider making a change using a private session to avoid affecting the rest of the system Measuring the Post Change SQL Performance After performing the system change create a post change SQL trial It is highly recommended that you create the post change SQL trial using the same method
132. ed Workload Replay Monitoring an Active Workload Replay This section describes how to monitor an active workload replay using Enterprise Manager To monitor an active workload replay 1 On the Software and Support page under Real Application Testing click Database Replay The Database Replay page appears Under Active Capture and Replay select the workload replay you want to monitor and click View The View Workload Replay page appears Replaying a Database Workload 11 13 Monitoring Workload Replay Using Enterprise Manager View Workload Replay REPLAY x112 20100806174324 Y Summary Aj Workload Profile Connection Mappings Chart Type Page Refreshed Aug 6 2010 5 50 10 PM PDT Refresh OK Status In Progress Stop Replay REPLAY x112 20100806174324 CAPTURE x112 20100806164334 Replay Name Capture Name Directory Object CAPTURE2 Duration hh mm ss 00 06 04 Database Name X112 Prepare Time Aug 6 2010 5 43 45 PM PDT DBID 2506747715 Start Time Aug 6 2010 5 44 06 PM PDT End Time n a Replay Error Code n a SQL Tuning Set Name REPLAY_x112_20100806_r_3134978 Replay Error Message None Replay Parameters Re Elapsed Time Comparison Assessing the Replay The Elapsed Time Comparison chart shows how much time the replayed workload has taken to accomplish the same amount of work as Capture captured Replay Elapsed Bf Capture Elapsed E Not Yet Replayed When the Repl
133. ed here If you choose to run the SQL Performance Analyzer on the production system then substitute the production system for the test system where applicable Analyzing the SQL performance effect of system changes using SQL Performance Analyzer involves the following steps as illustrated in Figure 2 1 Introduction to SQL Performance Analyzer 2 1 Figure 2 1 SQL Performance Analyzer Workflow Production Test Client Client Client Execute Make Execute Compare Fix SQL Change SQL e Regressed SQL 1 Capture the SQL workload that you intend to analyze and store it in a SQL tuning set as described in Capturing the SQL Workload on page 2 3 2 If you plan to use a test system separate from your production system then perform the following steps a Set up the test system to match the production environment as closely as possible b Transport the SQL tuning set to the test system For more information see Setting Up the Test System on page 2 4 3 On the test system create a SQL Performance Analyzer task as described in Creating a SQL Performance Analyzer Task on page 2 4 4 Build the pre change SQL trial by test executing or generating execution plans for the SQL statements stored in the SQL tuning set as described in Measuring the Pre Change SQL Performance on page 2 5 5 Perform the system change as described in Making a System Change on page 2 7 6 Build the post change SQL trial by re
134. ed in the DBA_WORKLOAD_CONNECTION_MAP view will be ignored and the connection string specified using the server parameter will be used If set to FALSE all replay threads will connect using the connection remappings stored in the DBA_WORKLOAD_CONNECTION_MAP view This is the default setting The following example shows how to run the wrc executable in replay mode gt wrc system password test mode replay replaydir replay In this example the wrc executable starts the replay client to replay the workload capture stored in a subdirectory named replay under the current directory After all replay clients have connected the database will automatically distribute workload capture streams among all available replay clients and workload replay can begin You can monitor the status of the replay clients using the VSWORKLOAD_ REPLAY_THREAD view After the replay finishes all replay clients will disconnect automatically Displaying Host Information You can display the hosts that participated in a workload capture and workload replay by running the wrc executable in list_hosts mode In list_hosts mode the wrc executable accepts the keyword replaydir which specifies the directory that contains the preprocessed workload capture you want to replay If unspecified it defaults to the current directory The following example shows how to run the wrc executable in list_hosts mode
135. edentials enter the username and password for the database that will used for the workload capture The user needs the DBA privilege in order to restart the database This section only appears if the database will be restarted before workload capture Click Next The Capture Workload Review page appears Capture Workload Review Database x112 Cancel Back Step 5 of 5 Submit Logged In As IMMCHAN Review the following settings for capturing the workload Job Name CAPTURE X112 20100806163450 Capture Name CAPTURE x112 20100806163450 Directory Object CAPTURE1 Start Time Immediately Capture Duration Not Specified Capture SQL Tuning Set Yes Database Restart Restart Database No Workload Filters Excluded Sessions Filter Name Type Session Attribute Value Oracle Management Service DEFAULT Excluded Program OMS Oracle Management Agent DEFAULT Excluded Program emagent 9 Review the job settings for the workload capture that have been defined To run the job click Submit To make changes click Back To cancel the workload capture without saving changes click Cancel 10 Depending on the job settings that have been defined If the job is scheduled to start immediately and the database will be restarted the Confirmation Restart Database page appears To restart the database click Yes The Information Restart Database page appears while the database is being restarted Once the database is restarted
136. en the replay filter set is created 11 4 Oracle Database Real Application Testing User s Guide Steps for Replaying a Database Workload Setting Up Replay Clients The replay client is a multithreaded program an executable named wrc located in the SORACLE_HOME bin directory where each thread submits a workload from a captured session Before replay begins the database will wait for replay clients to connect At this point you need to set up and start the replay clients which will connect to the replay system and send requests based on what has been captured in the workload Before starting replay clients ensure that the a Replay client software is installed on the hosts where it will run a Replay clients have access to the replay directory a Replay directory contains the preprocessed workload capture a Replay user has the correct user ID password and privileges the replay user needs the DBA role and cannot be the SYS user a Replay clients are not started on a system that is running the database a Replay clients read the capture directory on a file system that is different from the one on which the database files reside To do this copy the capture directory to the system where the replay client will run After the replay is completed you can delete the capture directory After these prerequisites are met you can proceed to set up and start the replay clients using the wrc executable The wrc executable uses the foll
137. eported in a system generated SQL Performance Analyzer report Note To create an analysis task for other types of system changes use the guided workflow instead as described in Using the Guided Workflow on page 3 12 To use the SQL Performance Analyzer parameter change workflow 1 On the SQL Performance Analyzer page under SQL Performance Analyzer Workflows click Parameter Change The Parameter Change page appears Parameter Change Task Information Task Name SQL Tuning Set x Description Creation Method Execute SQLs J Per SQL Time Limit 5 minutes i TIP Time limit is on elapsed time of test execution of SQL Parameter Change Parameter Name M Base Value Changed Value Trial Comparison Comparison Metric Elapsed Time v Schedule Time Zone America Los_Angeles Immediately O Later Dap OTA AO EEE example Jun 3 200 Time 6 59 40 AM OPM 2 Inthe Task Name field enter the name of the task Creating an Analysis Task 3 3 Creating an Analysis Task Using Enterprise Manager 3 Inthe SQL Tuning Set field enter the name of the SQL tuning set that contains the SQL workload to be analyzed Alternatively click the search icon to search for a SQL tuning set using the Search and Select SQL Tuning Set window The selected SQL tuning set now appears in the SQL Tuning Se
138. er SQL statement for each SQL trial Moreover the SQL statements are executed in a more authentic environment because Database Replay captures all bind values and reproduces dynamic session state such as PL SQL package state more accurately It is recommended that you run SQL Performance Analyzer test execute first as a sanity test to ensure SQL statements have not regressed and the test system is set up properly before using Database Replay to perform load and currency testing Besides using replay divergence information to analyze replay characteristics of a given system change you should also use an application level validation procedure to assess the system change Consider developing a script to assess the overall success of the replay For example if 10 000 orders are processed during workload capture you should validate that a similar number of orders are also processed during replay After the replay analysis is complete you can restore the database to its original state at the time of workload capture and repeat workload replay to test other changes to the system See Also Chapter 12 Analyzing Replayed Workload for information about how to analyze data and performance divergence using Database Replay reports 8 4 Oracle Database Real Application Testing User s Guide 9 Capturing a Database Workload This chapter describes how to capture a database workload on the production system The first step in using Database
139. er is only valid with Oracle Database 10g Release 2 10 2 and cannot be used with subsequent releases To enable the workload capture feature on a system running Oracle Database 10g Release 2 run the wrrenb1 sql script at the SQL prompt SORACLE_HOME rdbms admin wrrenbl sql The wrrenbl1 sql script calls the ALTER SYSTEM SQL statement to set the PRE_ 11G_ENABLE_CAPTURE initialization parameter to TRUE If a server parameter file spfile is being used the PRE_11G_ENABLE_CAPTURE initialization parameter will be modified for the currently running instance and recorded in the spfile so that the new setting will persist when the database is restarted If a spfile is not being used the PRE_11G_ENABLE_CAPTURE initialization parameter will only be modified for the currently running instance and the new setting will not persist when the database is restarted To make the setting persistent without using a spfile you will need to manually specify the parameter in the initialization parameter file init ora To disable workload capture run the wrrdsb1 sql script at the SQL prompt SORACLE_HOME rdbms admin wrrdsbl sql The wrrdsb1 sq1 script calls the ALTER SYSTEM SQL statement to set the PRE_ 11G_ENABLE_CAPTURE initialization parameter to FALSE If a server parameter file spfile is being used the PRE_11G_ENABLE_CAPTURE initialization parameter will be modified for the currently running instance
140. er system For information about transporting SQL tuning sets using a Oracle Enterprise Manager see Oracle Database 2 Day Performance Tuning Guide a APIs see Oracle Database Performance Tuning Guide 4 On the SQL Performance Analyzer system create a SQL Performance Analyzer task using the SQL tuning set as its input source 7 10 Oracle Database Real Application Testing User s Guide Upgrading from Oracle Database 10g Release 2 and Newer Releases Remotely test execute the SQL statements in the SQL tuning set on the test system over a database link to build a pre upgrade SQL trial that will be used as a baseline for comparison as described in Testing Database Upgrades from Oracle Database 10g Release 2 and Newer Releases on page 7 11 5 Upgrade the test system 6 Remotely test execute the SQL statements a second time on the upgraded test system over a database link to build a post upgrade SQL trial as described in Testing Database Upgrades from Oracle Database 10g Release 2 and Newer Releases on page 7 11 7 Compare SQL performance and fix regressed SQL SQL Performance Analyzer compares the performance of SQL statements read from the SQL tuning set during the pre upgrade SQL trial to those captured from the remote test execution during the post upgrade SQL trial A report is produced to identify any changes in execution plans or performance of the SQL statements If the report reveals any regressed SQL statements y
141. ers Once the mapping table is created you can use Data Pump to transport it to the SQL Performance Analyzer system See Also a Oracle Database Utilities for information about using Data Pump Building a SQL Tuning Set Once the SQL trace files and mapping table are moved to the SQL Performance Analyzer system you can build a SQL tuning set using the DBMS_SQLTUNE package To build a SQL tuning set 1 Copy the SQL trace files to a directory on the SQL Performance Analyzer system 2 Create a directory object for this directory 7 4 Oracle Database Real Application Testing User s Guide Upgrading from Oracle9i Database and Oracle Database 10g Release 1 3 Use the DBMS_SQLTUNE SELECT_SQL_TRACE function to read the SQL statements from the SQL trace files For each SQL statement only information for a single execution is collected The execution frequency of each SQL statement is not captured Therefore when performing a comparison analysis for a production system running Oracle Database 10g Release 1 and older releases you should ignore the workload level statistics in the SQL Performance Analyzer report and only evaluate performance changes on an execution level The following example reads the contents of SQL trace files stored in the sql_ trace_prod directory object and loads them into a SQL tuning set DECLARE cur sys_refcursor BEGIN DBMS_SQLTUNE CREATE_SQLSET my_sts_9i OPEN cur FOR
142. executing the SQL statements in the SQL tuning set on the post change test system as described in Measuring the Post Change SQL Performance on page 2 7 2 2 Oracle Database Real Application Testing User s Guide Capturing the SQL Workload 7 Compare and analyze the pre change and post change versions of performance data and generate a report to identify the SQL statements that have improved remained unchanged or regressed after the system change as described in Comparing Performance Measurements on page 2 7 8 Tune any regressed SQL statements that are identified as described in Fixing Regressed SQL Statements on page 2 8 9 Ensure that the performance of the tuned SQL statements is acceptable by repeating steps 6 through 8 until your performance goals are met For each comparison you can use any previous SQL trial as the pre change SQL trial and the current SQL trial as the post change SQL trial For example you may want to compare the first SQL trial to the current SQL trial to assess the total change or you can compare the most recent SQL trial to the current SQL trial to assess just the most recent change Note Oracle Enterprise Manager provides automated workflows for steps 3 through 9 to simplify this process Capturing the SQL Workload Before running SQL Performance Analyzer capture a set of SQL statements on the production system that represents the SQL workload which you intend to analyze The
143. formance The SQL Performance Analyzer report can be viewed as an HTML text or active report Active reports provides in depth reporting using an interactive user interface that enables you to perform detailed analysis even when disconnected from the database or Oracle Enterprise Manager Introduction to SQL Performance Analyzer 2 7 Fixing Regressed SQL Statements See Also Chapter 6 Comparing SQL Trials for information about comparing performance measurements and reporting Fixing Regressed SQL Statements If the performance analysis performed by SQL Performance Analyzer reveals regressed SQL statements then you can make changes to remedy the problem For example you can fix regressed SQL by running SQL Tuning Advisor or using SQL plan baselines You can then repeat the process of executing the SQL statements and comparing its performance to the first execution Repeat these steps until you are satisfied with the outcome of the analysis See Also a Chapter 6 Comparing SQL Trials for information about fixing regressed SQL statements 2 8 Oracle Database Real Application Testing User s Guide 3 Creating an Analysis Task Once you have captured a SQL workload that you want to analyze into a SQL tuning set you can run SQL Performance Analyzer to analyze the effects of a system change on SQL performance To run SQL Performance Analyzer you must first create a SQL Performance Analyzer task A task is a container t
144. formation that can be used to assess the validity of the workload capture Using the information provided in this report you can determine if the captured workload a Represents the actual workload you want to replay a Does not contain any workload you want to exclude Can be replayed The information contained in the workload capture report are divided into the following categories a Details about the workload capture such as the name of the workload capture defined filters date time and SCN of capture a Overall statistics about the workload capture such as the total DB time captured and the number of logins and transactions captured and the corresponding percentages with respect to total system activity a Profile of the captured workload a Profile of the workload that was not captured due to version limitations a Profile of the uncaptured workload that were excluded using defined filters a Profile of the uncaptured workload that consists of background process or scheduled jobs Using Workload Replay Reports Workload replay reports contain information that can be used to measure performance differences between the capture system and the replay system The following sections describe how to generate and review workload replay reports a Generating Workload Replay Reports Using Enterprise Manager a Generating Workload Replay Reports Using APIs a Reviewing Workload Replay Reports Generating Workload Replay Reports Using
145. fresh the status icon click Refresh Depending on the amount of performance data collected from the pre change and post change executions the comparison analysis may take a long time to complete After the comparison analysis is completed the Status icon changes to a check mark and the Execute icon for the next step is enabled 6 Once SQL Performance Analyzer has analyzed the pre change and post change performance data generate a SQL Performance Analyzer report that you can use for further analysis On the Guided Workflow page click the Execute icon for View Trial Comparison Report The SQL Performance Analyzer Task Report page appears Review the report as described in Reviewing the SQL Performance Analyzer Report Using Oracle Enterprise Manager on page 6 3 Reviewing the SQL Performance Analyzer Report Using Oracle Enterprise Manager When a SQL Performance Analyzer task is completed the resulting data is generated into a SQL Performance Analyzer report that compares the pre change and post change SQL performance Figure 6 1 shows a sample SQL Performance Analyzer report This sample report uses the elapsed time comparison metric to compare the pre change and post change executions of a SOL workload Comparing SQL Trials 6 3 Comparing SQL Trials Using Oracle Enterprise Manager Figure 6 1 SQL Performance Analyzer Report SQL Performance Analyzer Task Report IMMCHAN SPA_GUIDED_WORKFLOW Save Mail SQL Tuning Set
146. g Advisor Doing so instructs the optimizer to use the original execution plans for these SQL statements in the future To create SQL plan baselines for the original plans first create a subset of a SQL tuning set of only the regressed SQL statements Next create SQL plan baselines for this subset of SQL statements by loading their plans using the LOAD_PLANS_FROM SQLSET function of the DBMS_SPM package as shown in the following example DECLARE my_plans PLS_INTEGER BEGIN my_plans DBMS _SPM LOAD_PLANS_FROM_SQLSET sqlset_name gt regressed_sql END See Also a Oracle Database Performance Tuning Guide for information about using SQL plan baselines a Oracle Database PL SQL Packages and Types Reference for information about the DBMS_SPM package Using SQL Performance Analyzer Views You can query the following views to monitor SQL Performance Analyzer and view its analysis results Note The information available in these views are also contained in the SQL Performance Analyzer report It is recommended that you use the SQL Performance Analyzer report to view analysis results instead Consider using these views only for performing more advanced analysis of the results a The DBA_ADVISOR_TASKS and USER_ADVISOR_TASKS views display descriptive information about the SQL Performance Analyzer task that was created a The DBA_ADVISOR_EXECUTIONS and USER_ADVISOR_EXEC
147. g Set field In the Description field optionally enter a description of the task In the Creation Method field select Execute SQLs to generate both execution plans and statistics for each SQL statement in the SQL tuning set by actually running the SQL statements remotely on the test system over a public database link Generate Plans to create execution plans remotely on the test system over a public database link without actually running the SQL statements In the Per SQL Time Limit list determine the time limit for SQL execution during the trial by performing one of the following actions Select 5 minutes Testing a Database Upgrade 7 7 Upgrading from Oracle9i Database and Oracle Database 10g Release 1 The execution will run each SQL statement in the SQL tuning set up to 5 minutes and gather performance data a Select Unlimited The execution will run each SQL statement in the SQL tuning set to completion and gather performance data Collecting execution statistics provides greater accuracy in the performance analysis but takes a longer time Using this setting is not recommended because the task may be stalled by one SQL statement for a prolonged time period a Select Customize and enter the specified number of seconds minutes or hours 6 Inthe Database Link field enter the global name of a public database link connecting to a user with the EXECUTE privilege for the DBMS_SQLPA package and the ADVISOR privilege on
148. g the SQL statements In the Per SQL Time Limit list determine the time limit for SQL execution during the trial by performing one of the following actions a Select 5 minutes The execution will run each SQL statement in the SQL tuning set up to 5 minutes and gather performance data a Select Unlimited The execution will run each SQL statement in the SQL tuning set to completion and gather performance data Collecting execution statistics provides greater accuracy in the performance analysis but takes a longer time Using this setting is not recommended because the task may be stalled by one SQL statement for a prolonged time period a Select Customize and enter the specified number of seconds minutes or hours In the Database Link field enter the global name of a public database link connecting to a user with the EXECUTE privilege for the DBMS_SQLPA package and the ADVISOR privilege on the pre upgrade system Alternatively click the search icon to search for and select a database link or click Create Database Link to create a database link using the Create Database Link page Under Post upgrade Trial a Select Use the same system as in the pre upgrade trial to use the same system for executing both the pre upgrade and post upgrade trials Oracle recommends using this option to avoid possible errors due to different system configurations When using this option you will need to upgrade the test data
149. ge cells to the database if Oracle Exadata is being used In both SQL trials the SQL statements are executed to completion and I O interconnect bytes measurements are taken as the actual and simulated Exadata values for the first and second trials respectively The measured change in I O interconnect bytes provides a good estimate of how much filtering can be performed in the Exadata storage cells and in turn the amount of CPU that normally would be used to process this data but now can be offloaded from the database Note Using the Exadata simulation will not result in any plan changes Execution plans do not change in an Exadata Storage Server installation because the simulation focuses on measuring the improvement in I O interconnect usage Moreover I O interconnect bytes will not increase except when data compression is used see next note because Oracle Exadata will only decrease the amount of data sent to the database Note Because I O interconnect bytes is the only metric used to measure the performance change impact of using an Exadata Storage Server installation it will not work properly if Oracle Exadata is used with data compression Since Exadata storage cells also decompress data the I O interconnect bytes with Oracle Exadata or the second SQL trial of a SQL statement may be greater than the I O interconnect bytes without Oracle Exadata or the first SQL trial where the data is compressed This comparison
150. grade Note For information about using SQL Performance Analyzer in other cases see SQL Performance Analyzer on page 1 1 Upgrading from Oracle9i Database and Oracle Database 10g Release 1 As illustrated in Figure 7 1 SQL Performance Analyzer supports testing database upgrades of Oracle9i Database and Oracle Database 10g Release 1 to Oracle Database 10g Release 2 and later releases by building a SQL tuning set from SQL trace files captured on the production system executing the SQL tuning set on the upgraded database remotely over a database link and then comparing the results to those captured on the production system Because SQL Performance Analyzer only accepts a set of SQL statements stored in a SQL tuning set as its input source and SQL tuning sets are not supported in Oracle9i Database a SQL tuning set must be constructed so that it can be used as an input source for SQL Performance Analyzer if you are upgrading from Oracle9i Database Testing a Database Upgrade 7 1 Upgrading from Oracle9i Database and Oracle Database 10g Release 1 Figure 7 1 SQL Performance Analyzer Workflow for Database Upgrade from Oracle9i to Oracle Database 10g Release 2 Oracle9i Database Production SQL Trace subset of sessions Mapping Table Remote Test execute db link Plan Stats Oracle Database Compare Perf View Report 10 2 0 2 or higher Test The production system which you are upgrading from should
151. hat encapsulates all of the data about a complete SQL Performance Analyzer analysis A SQL Performance Analyzer analysis comprises of at least two SQL trials and a comparison A SQL trial captures the execution performance of a SQL tuning set under specific environmental conditions and can be generated automatically using SQL Performance Analyzer by one of the following methods a Test executing SQL statements Generating execution plans for SQL statements a Referring to execution statistics and plans captured in a SQL tuning set When creating a SQL Performance Analyzer task you will need to select a SQL tuning set as its input source The SQL tuning set will be used as the source for test executing or generating execution plans for SQL trials Thus performance differences between trials are caused by environmental differences For more information see Creating a SQL Performance Analyzer Task on page 2 4 This chapter described how to create a SQL Performance Analyzer task and contains the following topics a Creating an Analysis Task Using Enterprise Manager a Creating an Analysis Task Using APIs Note The primary interface for running SQL Performance Analyzer is Oracle Enterprise Manager If for some reason Oracle Enterprise Manager is unavailable you can run SQL Performance Analyzer using the DBMS_SQLPA PL SQL package Tip Before running SQL Performance Analyzer capture the SQL workload to be used in the pe
152. he optimizer statistics workflow to analyze how changes to optimizer statistics will affect SQL performance as described in Using the Optimizer Statistics Workflow on page 3 6 a Exadata Simulation Use the Exadata simulation workflow to simulate how using Oracle Exadata will affect SQL performance as described in Using the Exadata Simulation Workflow on page 3 9 a Guided workflow Use the guided workflow to compare SQL performance for all other types of system changes as described in Using the Guided Workflow on page 3 12 3 2 Oracle Database Real Application Testing User s Guide Creating an Analysis Task Using Enterprise Manager Using the Parameter Change Workflow The parameter change workflow enables you to test the performance effect on a SQL workload when you change the value of a single environment initialization parameter For example you can compare SQL performance by setting the OPTIMIZER_ FEATURES_ENABLE initialization parameter set to 10 2 0 4 and 11 2 0 1 After you select a SQL tuning set and a comparison metric SOL Performance Analyzer creates a task and performs a trial with the initialization parameter set to the original value SQL Performance Analyzer then performs a second trial with the parameter set to the changed value by issuing an ALTER SESSION statement The impact of the change is thus contained locally to the testing session Any regression or change in performance is r
153. here are many ways to create a test database For example you can use the DUPLICATE command of Recovery Manager RMAN Oracle Data Pump or transportable tablespaces Oracle recommends using RMAN because it can create the test database from pre existing backups or from the active production datafiles The production and test databases can reside on the same host or on different hosts You should configure the test database environment to match the database environment of the production system as closely as possible In this way SQL Performance Analyzer can more accurately forecast the effect of the system change on SQL performance After the test system is properly configured export the SQL tuning set from the production system to a staging table then import it from the staging table into the test system See Also a Oracle Database Backup and Recovery User s Guide for information about duplicating a database with RMAN a Oracle Database 2 Day Performance Tuning Guide for information about transporting SQL tuning sets using Oracle Enterprise Manager a Oracle Database Performance Tuning Guide for information about transporting SQL tuning sets using APIs Creating a SQL Performance Analyzer Task After the SQL workload is captured and transported to the test system and the initial database environment is properly configured you can run SQL Performance Analyzer to analyze the effects of a system change on SQL performance 2 4
154. his page contains the following sections a SQL Tuning Set This section summarizes information about the SQL tuning set including its name owner description and the number of SQL statements it contains a SQL Trials Creating an Analysis Task 3 5 Creating an Analysis Task Using Enterprise Manager This section includes a table that lists the SQL trials used in the SQL Performance Analyzer task SQL Trial Comparisons This section contains a table that lists the results of the SQL trial comparisons 12 Click the icon in the Comparison Report column The SQL Performance Analyzer Task Result page appears 13 Review the results of the performance analysis as described in Reviewing the SQL Performance Analyzer Report Using Oracle Enterprise Manager on page 6 3 14 In cases when regression are identified click the icon in the SQL Tune Report column to view a SQL tuning report Using the Optimizer Statistics Workflow The optimizer statistics workflow enables you to analyze the effects of optimizer statistics changes on the performance of a SQL workload SQL Performance Analyzer tests the effect of new optimizer statistics by enabling pending optimizer statistics in the testing session The first SQL trial measures the baseline SQL tuning set performance the second SQL trial uses the pending optimizer statistics You can then run a comparison report for the two SQL trials To use the optimizer statistics workflow 1 O
155. hod can be useful in helping you investigate issues identified by SQL Performance Analyzer You can run SQL Performance Analyzer to test a database upgrade from Oracle Database 10g Release 2 or a newer release using Oracle Enterprise Manager or APIs as described in the following sections a Testing Database Upgrades from Oracle Database 10g Release 2 and Newer Releases Using Enterprise Manager a Testing Database Upgrades from Oracle Database 10g Release 2 and Newer Releases Using APIs Testing Database Upgrades from Oracle Database 10g Release 2 and Newer Releases Using Enterprise Manager To test a database upgrade from Oracle Database 10g Release 2 or a newer release using SQL Performance Analyzer Testing a Database Upgrade 7 11 Upgrading from Oracle Database 10g Release 2 and Newer Releases 1 On the Software and Support page under Real Application Testing click SOL Performance Analyzer The SQL Performance Analyzer page appears 2 Under SQL Performance Analyzer Workflows click Upgrade from 10 2 or 11g The Upgrade from 10 2 or 11g page appears Upgrade from 10 2 or 11g Task Information Task Name SQL Tuning Set Description Pre upgrade Trial Creation Method Execute SQLs Per SQL Time Limit 5 minutes TIP Time limit is on elapsed time of test execution of SQL Database Link g x Create Database Link TIP Provide a PUBLIC database link connecting to a remote
156. icking Save to File 10 To return to the Database Replay page click OK Replaying a Database Workload Using APIs This section describes how to replay a database workload using the DBMS_ WORKLOAD_REPLAY package You can also use Oracle Enterprise Manager to replay a database workload as described in Replaying a Database Workload Using Enterprise Manager on page 11 8 Replaying a database workload using the DBMS_WORKLOAD_REPLAY package is a multi step process that involves Initializing Replay Data Connection Remapping Setting Workload Replay Options Defining Workload Replay Filters and Replay Filter Sets Setting the Replay Timeout Action Starting a Workload Replay Pausing a Workload Replay 11 18 Oracle Database Real Application Testing User s Guide Replaying a Database Workload Using APIs a Resuming a Workload Replay a Cancelling a Workload Replay a Exporting AWR Data for Workload Replay See Also a Oracle Database PL SQL Packages and Types Reference for information about the DBMS_WORKLOAD_REPLAY package Initializing Replay Data After the workload capture is preprocessed and the test system is properly prepared the replay data can be initialized Initializing replay data loads the necessary metadata into tables required by workload replay For example captured connection strings are loaded into a table where they can be remapped for replay To initialize replay data
157. ilter_set parameter specifies the name of the filter set to create The default_action parameter determines if every captured database call should be replayed and whether the workload replay filters should be considered as inclusion or exclusion filters If this parameter is set to INCLUDE all captured database calls will be replayed except for the part of the workload defined by the replay filters In this case all replay filters will be treated as exclusion filters since they will define the part of the workload that will not be replayed This is the default behavior If this parameter is set to EXCLUDE none of the captured database calls will be replayed except for the part of the workload defined by the replay filters In this case all replay filters will be treated as inclusion filters since they will define the part of the workload that will be replayed Using a Replay Filter Set Once the replay filter set is created and the replay is initialized you can use the replay filter set to filter the replay in the replay_dir directory To use a replay filter set use the USE_FILTER_SET procedure BEGIN DBMS_WORKLOAD_REPLAY USE_FILTER_SET filter_set gt replayfilters END In this example the USE_FILTER_SET procedure uses the filter set named replayfilters The USE_FILTER_SET procedure in this example uses the filter_set required parameter which specifies the na
158. ir required parameter specifies a directory object pointing to the directory where the captured workload will be stored The duration parameter specifies the number of seconds before the workload capture will end If a value is not specified the workload capture will continue until the FINISH_CAPTURE procedure is called a The capture_sts parameter specifies whether to capture a SQL tuning set in parallel with the workload capture If this parameter is set to TRUE you can capture a SQL tuning set during workload capture then capture another SQL tuning set during workload replay and use SQL Performance Analyzer to compare the SQL tuning sets without having to re execute the SQL statements This enables you to obtain a SQL Performance Analyzer report and compare the SQL performance before and after the change while running Database Replay You can also export the resulting SQL tuning set with its AWR data using the EXPORT_AWR procedure as described in Exporting AWR Data for Workload Capture on page 9 16 This feature is not supported for Oracle RAC Workload capture filters that are defined using DBMS_WORKLOAD_CAPTURE do not apply to the SQL tuning set capture The default value for this parameter is FALSE a The sts_cap_interval parameter specifies the duration of the SQL tuning set capture from the cursor cache in seconds The default value is 300 Setting the value of this parameter below the defa
159. is a Oracle Database PL SQL Packages and Types Reference for information about the DBMS_SQLTUNE package Tuning Regressed SQL Statements From a Remote SQL Trial Using APIs If you chose to execute the SQL workload remotely on a separate database then you should tune any regressions identified by the SQL trials on the remote database instead of the system where the SQL Performance Analyzer task resides To tune regressed SQL statements from a remote SQL trial 1 On the system running SQL Performance Analyzer create a subset of the regressed SQL statements as a SQL tuning set DECLARE sqlset_cur DBMS_SQLTUNE SQLSET_CURSOR BEGIN DBMS_SQLTUNE CREATE_SQLSET SUB_STS1 test purpose OPEN sqlset_cur FOR SELECT value p FROM table DBMS_SQLTUNE SELECT_SQLPA_TASK task_name gt SPA_TASK1 execution_name gt COMP level_filter gt REGRESSED p DBMS_SQLTUNE LOAD_SQLSET SUB_STS1 sqlset_cur CLOSE sqlset_cur END Other than REGRESSED you can use other filters to select SQL statements for the SQL tuning set such as CHANGED ERRORS or CHANGED_PLANS For more information see Oracle Database PL SQL Packages and Types Reference 2 Create a staging table to where the SQL tuning set will be exported BEGIN DBMS_SQLTUNE CREATE_STGTAB_SQLSET table_name gt STG_TABI1 schema_name gt JOHNDOE tablespace_name gt TBS_1 6 24 Oracle Dat
160. is section describes how to stop an active workload capture using Enterprise Manager Capturing a Database Workload 9 11 Monitoring Workload Capture Using Enterprise Manager To stop an active workload capture 1 On the Software and Support page under Real Application Testing click Database Replay The Database Replay page appears 2 Under Active Capture and Replay select the workload capture you want to stop and click Stop The Confirmation page appears 3 To confirm that you want to stop the workload capture click Yes Once the workload capture is stopped the Export AWR Data page appears 4 To export the Automatic Workload Repository AWR data click Yes The Export AWR Data page appears click Yes Exporting AWR data enables detailed analysis of the workload This data is also required if you plan to run the Replay Compare Period report or the AWR Compare Period report on a pair of workload captures or replays If you choose not to export AWR data click No You can still export AWR data from a completed workload capture at a later time from the View Workload Capture History page The View Workload Capture page appears See Also Oracle Database Performance Tuning Guide for information about the AWR Managing a Completed Workload Capture This section describes how to manage a completed workload capture using Enterprise Manager To manage a completed workload capture 1 On the Software and Support
161. izer to avoid performance regressions by using execution plans with known performance characteristics If a performance 6 8 Oracle Database Real Application Testing User s Guide Comparing SQL Trials Using Oracle Enterprise Manager regression occurs due to plan changes a SQL plan baseline can be created and used to prevent the optimizer from picking a new regressed execution plan To create SQL plan baselines 1 On the SQL Performance Analyzer Task Result page under Recommendations click Create SQL Plan Baselines The Create SQL Plan Baselines page appears The Regressed SQL Statements section lists the regressed SQL statements that will be associated with the new SQL plan baselines 2 Under Job Parameters specify the parameters for the job a Inthe Job Name field enter a name for the job b Inthe Description field optionally enter a description for the job 3 Under Schedule select a Immediately to start the job now a Later to schedule the job to start at a time specified using the Time Zone Date and Time fields 4 Click OK The SQL Performance Analyzer Task Result page appears A message is displayed to inform you that the job has been submitted successfully See Also a Oracle Database 2 Day Performance Tuning Guide for information about creating and managing SQL plan baselines Running SQL Tuning Advisor The SQL Tuning Advisor performs an in depth analysis of regressed SQL statements and attempt
162. jar SORACLE_HOME rdbms j1lib dbranalyzer jar oracle dbreplay workload checker CaptureChecker scratch capture jdbc oracle thin myhost mycompany com 1521 orcl Preprocessing a Database Workload 10 5 Preprocessing a Database Workload Using APIs 10 6 Oracle Database Real Application Testing User s Guide 11 Replaying a Database Workload After a captured workload is preprocessed it can be replayed repeatedly ona replay system that is running the same version of Oracle Database This chapter describes how to replay a database workload on the test system and contains the following sections a Setting Up the Test System Steps for Replaying a Database Workload a Replaying a Database Workload Using Enterprise Manager a Monitoring Workload Replay Using Enterprise Manager Replaying a Database Workload Using APIs a Monitoring Workload Replay Using APIs Tip Before you can replay a database workload you must first a Capture the workload on the production system as described in Chapter 9 Capturing a Database Workload a Preprocess the captured workload as described in Chapter 10 Preprocessing a Database Workload Setting Up the Test System Typically the replay system where the preprocessed workload will be replayed should be a test system that is separate from the production system Before a test system can be used for replay it must be prepared properly as described in the following sections a Rest
163. kload faster than the capture system If the value is over 100 percent the replay system processed the workload slower than the capture system a Database time The database time that is consumed in the time period that was captured is compared to the amount of database time that is consumed when replaying the workload Average active sessions The number of average active sessions captured in the workload is compared to the number of average active session that are replayed a User calls The number of user calls captured in the workload is compared to the number of user calls that are replayed To view the workload replay report click View Workload Replay Report For information about using the Workload Replay report see Reviewing Workload Replay Reports on page 12 5 7 To view the connection strings used in the capture and the replay systems click the Connection Mappings tab 8 To view replay parameters used by the workload replay click the Replay Parameters tab 9 To run a report click the Report tab 11 16 Oracle Database Real Application Testing User s Guide Monitoring Workload Replay Using Enterprise Manager Workload Profile Connection Mappings Replay Parameters Report Workload Replay Report Run Report Compare Period Report First Workload Capture or Replay CAPTURE x112 20100726181024 Jul 26 2010 6 12 45 PM x Second Workload Capture or Replay REPLAY x112 201007
164. kload must have been preprocessed and copied to the replay system A directory Cancel Set Up Replay object for the directory with the copied workload must exist in the replay system a aa Directory Select a directory object that contains the last replayed workload or a preprocessed workload Directory Object Create Directory Object 3 In the Directory Object list select a directory that contains the preprocessed workload that you want to replay After a directory is selected the Replay Workload page will be refreshed to display the Capture Summary and the Replay History sections For more information see Setting Up the Replay Directory on page 11 2 Replay Workload The captured workload must have been preprocessed and copied to the replay system A directory Cancel Set Up Replay object for the directory with the copied workload must exist in the replay system Directory Select a directory object that contains the last replayed workload or a preprocessed workload Directory Object CAPTURE1 v Create Directory Object Y Capture Summary Name CAPTURE x112 Captured Data Size MB 0 02 20100509051233 Duration hh mm ss 00 02 07 Status Completed Start Time May 9 2010 5 13 20 AM PDT Directory Object CAPTURE1 End Time May 9 2010 5 15 27 AM PDT Database Name X112 Start SCN 607434 Capture Database Version 11 2 0 2 0 End SCN 607778 DBID 2499870771 Preprocessed Database Version 11 2 0 2 0 Capture Error
165. lay Compare Period Report For information about using the Replay Compare Period report see Reviewing Replay Compare Period Reports on page 12 9 AWR Compare Period The AWR Compare Period report can be used to compare the AWR data in one workload capture or replay with another Before running this report AWR data for the captured or replayed workload must have been previously exported To run this report under Compare Period Report select the first and second workload captures or replays you want to compare and click Run AWR Compare Period Report If AWR data is not previously exported from the captured or replayed workload you will be prompted to import the AWR data before continuing For more information about the AWR Compare Period report see Oracle Database 2 Day Performance Tuning Guide a SQL Performance Analyzer Report Replaying a Database Workload 11 17 Replaying a Database Workload Using APIs The SQL Performance Analyzer report can be used to compare the SQL tuning sets in one workload capture or replay with another To run this report under Compare Period Report select the first and second workload captures or replays containing the SQL tuning sets you want to compare and click Run SQL Performance Analyzer Report For more information about the SQL Performance Analyzer report see Reviewing the SQL Performance Analyzer Report Using Oracle Enterprise Manager on page 6 3 AWR The AWR report shows the AWR data
166. lected In the Schedule section Creating an Analysis Task 3 7 Creating an Analysis Task Using Enterprise Manager a Inthe Time Zone list select your time zone code b Select Immediately to start the task now or Later to schedule the task to start at a time specified using the Date and Time fields 10 Click Submit The SQL Performance Analyzer page appears In the SQL Performance Analyzer Tasks section the status of this task is displayed To refresh the status icon click Refresh After the task completes the Status field changes to Completed SQL Performance Analyzer Tasks Delete View Latest Report Select Name SPA OPTIMIZER STATS IMMCHAN rag 26 2010 EXEC_3 Compare Completed 1584 of 1584 4 of 4 38 54 PM 11 In the SQL Performance Analyzer Tasks section select the task and click the link in the Name column The SQL Performance Analyzer Task page appears SQL Performance Analyzer Task IMMCHAN SPA_OPTIMIZER_STATS Miew Latest Report Page Refreshed Jul 26 2010 5 43 29 PM PDT Refresh The SQL Performance Analyzer Task is a container for experimental results of executing a specific SQL Tuning Set under changed environmental conditions and assessing the impact of environmental changes on STS execution performance SQL Tuning Set Y SQL Trials A SQL Trial captures the execution performance of the SQL Tuning Set under specific environmental conditions Create SQL Trial SQL Trial Name
167. ll first complete all active transactions and then disconnect the connected user before shutting down the database Abort An abort shutdown will shut down the database instantaneously by abort ing all active transactions Force the database to shutdown A force shutdown will shut down the database if any cluster managed database services are operational This option only appears if you are run ning Oracle RAC Under Database Startup Parameters select if the database will restart using the current default server parameter file spfile or a specific parameter file pfile To select a pfile enter the fully qualified name for the pfile This option only appears if the database will be restarted before workload capture After defining the parameters for the workload capture click Next The Capture Workload Schedule page appears Capture Workload Schedule Database x090422 Cancel Back Step 4 of 5 Next Back Step 4 of 5 Next Logged InAs IMMCHAN Caneel Cadi Job Parameters Job Name CAPTURE x090422 20090501114705 Description Job Schedule Choose a start time and a capture duration so that the workload you are interested in replaying at a later time can be captured Start Capture Duration Immediately Not Specified o Capture must be stopped manually duration is not specified pae Duration Date May 1 2009 ol Hours o minutes 0 exemple May 1 2003 Time 11 v 45 00
168. me and cost savings that the system change to the production environment will result in net improvement You can use the SQL Performance Analyzer to analyze the impact on SQL performance of any type of system changes including Introduction to Oracle Real Application Testing 1 1 Database Replay a Database upgrade a Configuration changes to the operating system or hardware Schema changes Changes to database initialization parameters a Refreshing optimizer statistics SQL tuning actions See Also a Part I SQL Performance Analyzer for information about using SQL Performance Analyzer Database Replay Before system changes are made such as hardware and software upgrades extensive testing is usually performed in a test environment to validate the changes However despite the testing the new system often experiences unexpected behavior when it enters production because the testing was not performed using a realistic workload The inability to simulate a realistic workload during testing is one of the biggest challenges when validating system changes Database Replay enables realistic testing of system changes by essentially re creating the production workload environment on a test system Using Database Replay you can capture a workload on the production system and replay it on a test system with the exact timing concurrency and transaction characteristics of the original workload This enables you to fully asses
169. me of the filter set to be used in the replay Setting the Replay Timeout Action This section describes how to set a timeout action for the workload replay You can set a replay timeout action to abort user calls that are significantly slower during replay or cause a replay to hang For example you may want to set a replay timeout action to abort runaway queries caused by sub optimal execution plans following a database upgrade When a replay timeout action is enabled a user call will exit with an ORA 15569 error if it is delayed beyond the conditions specified by the replay timeout action The aborted call and its error are reported as error divergence To set a replay timeout use the SET_REPLAY_TIMEOUT procedure BEGIN DBMS_WORKLOAD_REPLAY SET_REPLAY TIMEOUT enabled gt TRUE min_delay gt 20 max_delay gt 60 delay_factor gt 10 END In this example the SET_REPLAY_TIMEOUT procedure defines a replay timeout action that will abort a user call if the delay during replay is more than 60 minutes or if the delay during replay is over 20 minutes and the elapsed time is 10 times greater than the capture elapsed time Replaying a Database Workload 11 23 Replaying a Database Workload Using APIs The SET_REPLAY_TIMEOUT procedure in this example uses the following parameters The enabled parameter specifies if the replay timeout action is enabled or
170. med Preprocessing is resource intensive and should be performed on a system that is a Separate from the production system Running the same version of Oracle Database as the replay system For Oracle Real Application Clusters Oracle RAC select one database instance of the replay system for the preprocessing This instance must have access to the captured data files that require preprocessing which can be stored on a local or shared file system If the capture directory path on the capture system resolves to separate physical directories in each instance you will need to move all the capture files created in each of these directories into a single directory on which preprocessing will be performed Typically you will preprocess the captured workload on the replay system If you plan to preprocess the captured workload on a system that is separate from the replay system you will also need to move all preprocessed data files from the directory where they are stored on the preprocessing system to a directory on the replay system after preprocessing is complete This chapter contains the following sections a Preprocessing a Database Workload Using Enterprise Manager a Preprocessing a Database Workload Using APIs Tip Before you can preprocess a captured workload you need to capture the workload on the production system as described in Chapter 9 Capturing a Database Workload Preprocessing a Database Workload Using Enterprise Manage
171. mpare period report to perform a high level comparison of one workload replay to its capture or to another replay of the same capture Only workload replays that contain at least 5 minutes of database time can be compared using this report For information about how to interpret the replay compare period report see Reviewing Replay Compare Period Reports on page 12 9 AWR Compare Period report click Run AWR Compare Period Report Use the AWR compare period report to compare the AWR data from one workload replay to its capture or to another replay of the same capture For information about how to interpret AWR compare period reports see Oracle Database 2 Day Performance Tuning Guide SQL Performance Analyzer report click Run SQL Performance Analyzer Report If this is the first time you are generating a SQL Performance Analyzer report for the selected workload capture and workload replay then click Yes to submit a new scheduler job The SQL Performance Analyzer report can be used to compare a SQL tuning set from a workload capture to another SQL tuning set from a workload replay or two SQL tuning sets from two workload replays Comparing SQL tuning sets with Database Replay provides more information than SQL Performance Analyzer test execute because it considers and shows all execution plans for each SQL statement while SQL Performance Analyzer test execute generates only one execution plan per SQL statement for each SQL trial
172. ms of DB time and other such key attributes Before restarting the database determine an appropriate time to shut down the production database before the workload capture when it is the least disruptive For example you may want to capture a workload that begins at 8 00 a m However to avoid service interruption during normal business hours you may not want to restart the database during this time In this case you should consider starting the workload capture at an earlier time so that the database can be restarted at a time that is less disruptive Once the database is restarted it is important to start the workload capture before any user sessions reconnect and start issuing any workload Otherwise transactions performed by these user sessions will not be replayed properly in subsequent database replays because only the part of the transaction whose calls were executed after the workload capture is started will be replayed To avoid this problem consider restarting the database in RESTRICTED mode using STARTUP RESTRICT which will only allow the SYS user to login and start the workload capture By default once the workload capture begins any database instance that are in RESTRICTED mode will automatically switch to UNRESTRICTED mode and normal operations can continue while the workload is being captured Only one workload capture can be performed at any given time If you have
173. n the Capture bar the replay system is processing the workload faster than the capture system a User Call Progress To view this chart in the Chart Type field select User Call Progress Chart Type User Call Progress x 200 150 E Replay E Capture User Calls e o DO 05 LO WS 20 2S AO TRS 40 45 oO 55 6 0 Elapsed Time Minutes Network Time hh mm ss 00 00 01 Clients 1 Think Time hh mm ss 00 00 58 Clients Finished 1 The User Call Progress chart shows how much time it has taken to replay the same workload compared to the elapsed time during the workload capture in terms of user calls If the Replay line is above or to the left of the Capture line the replay system is processing the workload faster than the capture system If the workload capture was performed on an older version of Oracle Database then the Capture line may not appear in the User Call Progress chart because the user call data may be unavailable In this case import the user call data by clicking the Import User Call Data button which will appear next to the Chart Type list Under Divergence any error and data discrepancies between the replay system and the capture system are displayed as diverged database calls during replay The percentage of total calls that diverged can be used as a measure of the replay quality To view details about the diverged calls click the link that corresponds to the type of diverged call in the
174. n the SQL Performance Analyzer page under SQL Performance Analyzer Workflows click Optimizer Statistics The Optimizer Statistics page appears Optimizer Statistics Task Information Task Name SQL Tuning Set l ng Description E Creation Method Execute SQLs Per SQL Time Limit 5 minutes TIP Time limit is on elapsed time of test execution of SQL Trial Comparison Comparison Metric Elapsed Time v Schedule Time Zone Pacific Pago_Pago v Immediately O Later Date May 10 2010 example May 10 2010 2 Inthe Task Name field enter the name of the task 3 Inthe SQL Tuning Set field enter the name of the SQL tuning set that contains the SQL workload to be analyzed 3 6 Oracle Database Real Application Testing User s Guide Creating an Analysis Task Using Enterprise Manager Alternatively click the search icon to search for a SQL tuning set using the Search and Select SQL Tuning Set window The selected SQL tuning set now appears in the SQL Tuning Set field In the Description field optionally enter a description of the task In the Creation Method list determine how the SQL trial is created and what contents are generated by performing one of the following actions a Select Execute SQLs The SQL trial generates both execution plans and statistics for each SQL statement in the SQL tuning set by actually running the SQL statements
175. nalyzer to treat the statistics in the SQL tuning set as a trial execution Specify a name to identify the execution using the execut ion_name parameter If not specified then SQL Performance Analyzer automatically generates a name for the task execution The following example executes the SQL Performance Analyzer task named my_spa_ task as a trial execution EXEC DBMS_SQLPA EXECUTE_ANALYSIS_TASK task_name gt my_spa_task execution_type gt CONVERT SQLSET execution_name gt my_trial_9i To build the post upgrade SQL trial using APIs perform an explain plan or test execute using the SQL Performance Analyzer system by calling the EXECUTE_ ANALYSIS_TASK procedure Set the DATABASE_LINK task parameter to the global name of a public database link connecting to a user with the EXECUTE privilege for the DBMS_SQLPA package and the ADVISOR privilege on the test system If you choose to use EXPLAIN PLAN only execution plans will be generated Subsequent comparisons will only be able to yield a list of changed plans without making any conclusions about performance changes If you choose to use TEST EXECUTE the SQL workload will be executed to completion This effectively builds the post upgrade SQL trial using the statistics and execution plans generated from the test system Using TEST EXECUTE is recommended to capture the SQL execution
176. name is not case sensitive Specifies the schema where the mapping table resides If set to NULL the current schema will be used Testing a Database Upgrade 7 5 Upgrading from Oracle9i Database and Oracle Database 10g Release 1 Table 7 1 Cont DBMS_SQLTUNE SELECT_SQL_TRACE Function Parameters Parameter Description select_mode Specifies the mode for selecting SQL statements from the trace files The default value is SINGLE_EXECUTION In this mode only statistics for a single execution per SQL statement will be loaded into the SQL tuning set The statistics are not cumulative as is the case with other SQL tuning set data source table functions options Specifies the options for the operation The default value is LIMITED_COMMAND_TYPE only SQL types that are meaningful to SOL Performance Analyzer such as SELECT INSERT UPDATE and DELETE are returned from the SQL trace files pattern_start Specifies the opening delimiting pattern of the trace file sections to consider This parameter is currently not used pattern_end Specifies the closing delimiting pattern of the trace file sections to process This parameter is currently not used result_limit Specifies the top SQL from the filtered source The default value is 2 t which represents unlimited See Also Oracle Database PL SQL Packages and Types Reference for information about the DBMS_SQLTUNE package
177. nd SQLSET_OWNER should also be specified Specify a name to identify the execution using the execut ion_name parameter If not specified then SQL Performance Analyzer automatically generates a name for the task execution Specify execution parameters using the execution_params parameters The execution_params parameters are specified as name value pairs for the specified execution For example you can set the following execution parameters The time_limit parameter specifies the global time limit to process all SQL statements in a SQL tuning set before timing out The local_time_limit parameter specifies the time limit to process each SQL statement in a SQL tuning set before timing out To perform a remote test execute set the DATABASE_LINK task parameter to the global name of a public database link connecting to a user with the EXECUTE privilege for the DBMS_SQLPA package and the ADVISOR privilege on the test system To fully execute DML statements including acquiring row locks and modifying row set the EXECUTE_FULLDML parameter to TRUE SQL Performance Analyzer will issue a rollback after executing the DML statements to prevent persistent changes from being made The default value for this parameter is FALSE which executes only the query portion of the DML statement without modifying the data To restore the relevant captured init ora setti
178. nd Select SQL Tuning Set window The selected SQL tuning set now appears in the SQL Tuning Set field 4 Inthe Description field optionally enter a description of the task 5 Inthe Per SQL Time Limit list determine the time limit for SOL execution during the trial by performing one of the following actions a Select 5 minutes The execution will run each SQL statement in the SQL tuning set up to 5 minutes and gather performance data 3 10 Oracle Database Real Application Testing User s Guide Creating an Analysis Task Using Enterprise Manager Select Unlimited The execution will run each SQL statement in the SQL tuning set to completion and gather performance data Collecting execution statistics provides greater accuracy in the performance analysis but takes a longer time Using this setting is not recommended because the task may be stalled by one SQL statement for a prolonged time period Select Customize and enter the specified number of seconds minutes or hours 6 Inthe Schedule section a Inthe Time Zone list select your time zone code b Select Immediately to start the task now or Later to schedule the task to start at a time specified using the Date and Time fields 7 Click Submit The SQL Performance Analyzer page appears In the SQL Performance Analyzer Tasks section the status of this task is displayed To refresh the status icon click Refresh After the task completes the Status field changes
179. ng documents in the Oracle Database Release 11 2 documentation set Oracle Database 2 Day DBA Oracle Database 2 Day Performance Tuning Guide Oracle Database Administrator s Guide Oracle Database Concepts Oracle Database Performance Tuning Guide Conventions The following text conventions are used in this document Convention Meaning boldface Boldface type indicates graphical user interface elements associated with an action or terms defined in text or the glossary italic Italic type indicates book titles emphasis or placeholder variables for which you supply particular values monospace Monospace type indicates commands within a paragraph URLs code viii in examples text that appears on the screen or text that you enter 1 Introduction to Oracle Real Application Testing Oracle Real Application Testing option enables you to perform real world testing of Oracle Database By capturing production workloads and assessing the impact of system changes before production deployment Oracle Real Application Testing minimizes the risk of instabilities associated with changes Oracle Real Application Testing comprises two components a SQL Performance Analyzer a Database Replay SQL Performance Analyzer and Database Replay are complementary solutions that can be used for real application testing Depending on the nature and impact of the system change and on which system the test will be performed production o
180. ngs during a test execute set the APPLY_CAPTURED_COMPILENV parameter to TRUE This is not the default behavior because typically you are running SQL trials to test changes when changing the environment However this method may be used in cases when the init ora settings are not being changed such as creating an index This method is not supported for remote SQL trials The following example illustrates a function call made before a system change EXEC DBMS_SQLPA EXECUTE_ANALYSIS_TASK task_name gt my_spa_task 4 4 Oracle Database Real Application Testing User s Guide Creating a Pre Change SQL Trial Using APIs execution_type gt TEST EXECUTE execution_name gt my_exec_BEFORE_change Once the pre change performance data is built you can make the system change and build the post change performance data by re executing the SQL statements in the SQL tuning set on the post change test system as described in Chapter 5 Creating a Post Change SQL Trial See Also Oracle Database PL SQL Packages and Types Reference to learn about the DBMS_SQLPA EXECUTE_ANALYSIS_TASK function Creating a Pre Change SQL Trial 4 5 Creating a Pre Change SQL Trial Using APIs 4 6 Oracle Database Real Application Testing User s Guide 9 Creating a Post Change SQL Trial After computing the pre change SQL performance data you can perform the system change on the test system Before making
181. ning set on the post change test system as described in Chapter 5 Creating a Post Change SQL Trial Creating a Pre Change SQL Trial 4 3 Creating a Pre Change SQL Trial Using APIs Creating a Pre Change SQL Trial Using APIs This section describes how to build the pre change performance data by using the D BMS_SQLPA EXECUTE_ANALYSIS_TASK procedure Call the EXECUTE_ANALYSIS_TASK procedure using the following parameters Set the task_name parameter to the name of the SQL Performance Analyzer task that you want to execute Set the execut ion_type parameter in one of the following ways Set to EXPLAIN PLAN to generate execution plans for all SQL statements in the SQL tuning set without executing them Set to TEST EXECUTE recommended to execute all statements in the SQL tuning set and generate their execution plans and statistics When TEST EXECUTE is specified the procedure generates execution plans and execution statistics The execution statistics enable SQL Performance Analyzer to identify SQL statements that have improved or regressed Collecting execution statistics in addition to generating execution plans provides greater accuracy in the performance analysis but takes longer Set to CONVERT SQLSET to refer to a SQL tuning set for the execution statistics and plans for the SQL trial Values for the execution parameters SQLSET_NAME a
182. nitialization parameter changes use the simplified parameter change workflow instead as described in Using the Parameter Change Workflow on page 3 3 To use the SQL Performance Analyzer task guided workflow 1 On the SQL Performance Analyzer page under SQL Performance Analyzer Workflows click Guided Workflow The Guided Workflow page appears The guided workflow enables you to test the performance effect on a SQL workload when you perform any type of system changes as described in SQL Performance Analyzer on page 1 1 This page lists the required steps in the SQL Performance Analyzer task in sequential order Each step must be completed in the order displayed before the next step can begin Guided Workflow Page Refreshed May 1 2009 2 22 50 PM PDT Refresh view Data Real Time 15 Second Refresh The following guided workflow contains the sequence of steps necessary to execute a successful two trial SQL Performance Analyzer test Note Be sure that the Trial environment matches the tests you want to conduct Step Description Executed Status Execute 1 Create SQL Performance Analyzer Task based on SQL Tuning Set 5 B 2 Create SQL Trial in Initial Environment P 3 Create SQL Trial in Changed Environment E 4 Compare Step 2 and Step 3 P 5 View Trial Comparison Report 2 On the Guided Workflow page click the Execute icon for the Step 1 Create SQL Performance Analyzer Task based on SQL Tuning Set
183. nts Part I contains the following chapters a Chapter 2 Introduction to SQL Performance Analyzer a Chapter 3 Creating an Analysis Task a Chapter 4 Creating a Pre Change SQL Trial a Chapter 5 Creating a Post Change SQL Trial a Chapter 6 Comparing SQL Trials a Chapter 7 Testing a Database Upgrade 2 Introduction to SQL Performance Analyzer You can run SQL Performance Analyzer on a production system or a test system that closely resembles the production system Testing a system change on a production system will impact the system s throughput because SQL Performance Analyzer must execute the SQL statements that you are testing Any global changes made on the system to test the performance effect may also affect other users of the system If the system change does not impact many sessions or SQL statements then running SQL Performance Analyzer on the production system may be acceptable However for systemwide changes such as a database upgrade using a production system is not recommended Instead consider running SQL Performance Analyzer on a separate test system so that you can test the effects of the system change without affecting the production system Using a test system also ensures that other workloads running on the production system will not affect the analysis performed by SQL Performance Analyzer Running SQL Performance Analyzer on a test system is the recommended approach and the methodology describ
184. of Total Database Time hh mm ss 00 03 16 00 00 00 n a Average Active Sessions 0 31 0 00 n a User Calls 9 088 85 0 94 Transactions 9 770 0 n a Session Logins 52 11 MM 21 15 Application Errors n a 0 n a 3 Under Summary information about the workload capture is displayed 4 To view the workload profile click the Workload Profile tab Under Average Active Sessions the Active Sessions chart provides a graphic display of the captured session activity compared to the uncaptured session activity such as background activities or filtered sessions Under Comparison various statistics for the workload capture are displayed including database time average active sessions user calls transactions session logins and application errors The statistics for the total session activity are displayed in the Total column and the statistics for the captured session activity are displayed in the Capture column The Percentage of Total column displays the percentage of total session activity that are being captured in the workload To view the workload capture report click View Workload Capture Report 5 To view workload filters used by the workload capture click the Workload Filters tab Details about the workload filters used by the workload capture are displayed including the workload filter name type session attribute and value 6 To return to the Database Replay page click OK Stopping an Active Workload Capture Th
185. omparing SQL Trials 6 15 Comparing SQL Trials Using APIs Execution Statistics The Execution Statistics subsection compares execution statistics of the SQL statement from the pre change and post change executions and then summarizes the findings Example 6 6 shows the Execution Statistics subsection of a sample report Example 6 6 Execution Statistics Execution Statistics Impact on Value Value Impact Workload Workload Stat Name Workload Before After on SQL Before After elapsed_time 95 54 36 484 143 161 292 39 32 68 94 73 parse_time 12 37 004 062 1450 85 11 79 exec_elapsed 95 89 36 48 143 099 292 27 32 81 95 02 exec_cpu 19 73 36 467 58 345 59 99 32 89 88 58 buffer_gets 10 08 1653012 2160529 30 7 32 82 82 48 cost 2 17 11224 2771 75 31 16 16 4 66 reads 1825 72 4091 455280 11028 82 16 55 96 66 writes 1500 0 15 1500 0 100 rows 135 135 Before Change 1 The statement was first executed to warm the buffer cache 2 Statistics shown were averaged over next 9 executions After Change 1 The statement was first executed to warm the buffer cache 2 Statistics shown were averaged over next 9 executions Findings 2 1 The performance of this SQL has regressed 2 The structure of the SQL execution plan has changed Execution Plans The Execution Plans subsection displays the pre change and post change execution plans for the SQL statement
186. on frequency or importance of each SQL statement Impact of the system change on each SQL statement relative to the entire SQL workload Impact of the system change on each SQL statement a Whether the structure of the execution plan for each SQL statement has changed Example 6 3 shows the Performance Statistics of SQL Statements subsection of a sample report The report has been altered slightly to fit on the page Example 6 3 Performance Statistics of SQL Statements SQL Statements Sorted by their Absolute Value of Change Impact on the Workload Impact on Execution Metric Metric Impact Plan object id sql_id Workload Frequency Before After on SQL Change 205 73s2sgy2svfrw 29 01 100000 1681683 220590 86 883 y 206 gq2a407mv2hsy 29 01 949141 1681683 220590 86 88 y 204 2wtgxbjz6u2by 10 08 478254 1653012 2160529 30 7 y The SQL statements are sorted in descending order by the absolute value of the net impact on the SQL workload that is the sort order does not depend on whether the impact was positive or negative 6 14 Oracle Database Real Application Testing User s Guide Comparing SQL Trials Using APIs Errors The Errors subsection reports all errors that occurred during an execution An error may be reported at the SQL tuning set level if it is common to all executions in the SQL tuning set or at the execution level if it is specific to a SQL sta
187. onsider only the top number of SQL statements after filtering and ranking The following example illustrates a function call VARIABLE t_name VARCHAR2 100 EXEC t_name DBMS _SQLPA CREATE_ANALYSIS_TASK sqlset_name gt my_sts task_name gt my_spa_task Once the analysis task is created you can build the pre change performance data by executing the SQL statements stored in the SQL tuning set as described in Chapter 4 Creating a Pre Change SQL Trial See Also Oracle Database PL SQL Packages and Types Reference to learn more about the DBMS_SQLPA CREATE_ANALYSIS_TASK function Running the Exadata Simulation Using APIs This section describes how to run the Oracle Exadata simulation using APIs For information about how SQL Performance Analyzer simulates the effects of an Exadata Storage Server installation on the performance of a SQL workload see Using the Exadata Simulation Workflow on page 3 9 To enable Exadata simulation for an analysis task call the SET_ANALYSIS_TASK_ PARAMETER procedure before creating the post change SQL trial as shown in the following example EXEC DBMS_SQLPA SET_ANALYSIS_TASK_PARAMETER task_name gt my_spa_task parameter gt CELL_SIMULATION_ENABLED value gt TRUE This will enable Exadata simulation when you create the post change SQL trial which can then be compared to the pre change SQL trial that was created with Exadata simulation disabled
188. or ADDM SQL Tuning Advisor or SQL Access Advisor After you have made the system change you can build the post change version of performance data by executing the SQL workload again SQL Performance Analyzer will store the results from executing the SQL statements in a post change SQL trial For more information see Measuring the Post Change SQL Performance on page 2 7 This section described how to create the post change SQL trial and contains the following topics a Creating a Post Change SQL Trial Using Oracle Enterprise Manager a Creating a Post Change SQL Trial Using APIs Creating a Post Change SQL Trial 5 1 Creating a Post Change SQL Trial Using Oracle Enterprise Manager Note The primary interface for creating a post change SQL trial is Oracle Enterprise Manager If for some reason Oracle Enterprise Manager is unavailable you can create a post change SQL trial using the DBMS_SQLPA PL SQL package Tip Before making the system change creating a post change SQL trial you need to create a pre change SQL trial as described in Chapter 4 Creating a Pre Change SQL Trial Creating a Post Change SQL Trial Using Oracle Enterprise Manager This section describes how to collect the post change SQL performance data using Oracle Enterprise Manager To create a post change SQL trial using Enterprise Manager 1 On the Guided Workflow page click the Execute icon for the Create SQL Trial in Changed Environment ste
189. oring the Database Resetting the System Time Restoring the Database Before a workload can be replayed the application data state should be logically equivalent to that of the capture system at the start time of workload capture This minimizes replay divergence during replay The method for restoring the database depends on the backup method that was used before capturing the workload For example if RMAN was used to back up the capture system you can use RMAN DUPLICATE capabilities to create the test database For more information see Prerequisites for Capturing a Database Workload on page 9 1 Replaying a Database Workload 11 1 Steps for Replaying a Database Workload After the database is created with the appropriate application data on the test system perform the system change you want to test such as a database or operating system upgrade The primary purpose of Database Replay is to test the effect of system changes on a captured workload Therefore the system changes you make should define the test you are conducting with the captured workload Resetting the System Time It is recommended that the system time on the replay system host be changed to a value that approximately matches the capture start time just before replay is started Otherwise an invalid data set may result when replaying time sensitive workloads For example a captured workload that contains SQL statements using the SYSDATE and SYSTIMESTAMP fun
190. ort generated by comparing two SQL tuning sets 6 18 Oracle Database Real Application Testing User s Guide Comparing SQL Trials Using APIs Example 6 8 Analysis Information and Report Summary Analysis Information Before Change Execution After Change Execution Execution Name first trial Execution Name second trial Execution Type CONVERT SQLSET Execution Type CONVERT SQLSET Status COMPLETED Status COMPLETED Started Last Updated Before Change Workload After Change Workload SQL Tuning Set Name my_first_sts SQL Tuning Set Name my_second_sts SQL Tuning Set Owner APPS SQL Tuning Set Owner APPS Total SQL Statement Count 5 Total SQL Statement Count 6 Overall Impact 72 32 Improvement Impact 47 72 Regression Impact 02 Missing SQL Impact 33 1 New SQL Impact 8 48 SQL Statement Count SQL Category SQL Count Plan Change Count Overall 7 1 Common 4 1 Improved 3 1 Regressed 1 0 Different 3 0 Missing SQL 1 0 New SQL 2 0 As shown in Example 6 8 this report contains two additional categories that are not found in standard SQL Performance Analyzer reports both categories are grouped under the heading Different a Missing SQL This category represents all SQL statements that are present in the first SQL tuning set but are not found in the second SQL tuning set In this example only one SQL statement is missing As shown in Example 6 9 this SQL statement has Asql_id value
191. other SQL tuning set without having to re execute the SQL statements This enables you to obtain a SQL Performance Analyzer report and compare the SQL performance before and after the change while running Database Replay You can also export the resulting SQL tuning set with its AWR data using the EXPORT_AWR procedure as described in Exporting AWR Data for Workload Replay on page 11 25 This feature is not supported for Oracle RAC Workload replay filters that are defined using DBMS_WORKLOAD_REPLAY do not apply to the SQL tuning set capture The default value for this parameter is FALSE The sts_cap_interval parameter specifies the duration of the SQL tuning set capture from the cursor cache in seconds The default value is 300 Setting the value of this parameter below the default value may cause additional overhead with some workloads and is not recommended For more information about setting these parameters see Specifying Replay Options on page 11 3 Defining Workload Replay Filters and Replay Filter Sets This section describes how to add and remove workload replay filters and how to create and use replay filter sets For information about using workload filters and replay filter sets with workload replay see Using Filters with Workload Replay on page 11 4 This section contains the following topics Adding Workload Replay Filters Deleting Workload Replay Filters Creating a Replay Filter Set Using a
192. ou can make further changes to fix the regressed SQL as described in Tuning Regressed SQL Statements After Testing a Database Upgrade on page 7 15 Repeat the process of executing the SQL tuning set and comparing its performance to a previous execution to test any changes made until you are satisfied with the outcome of the analysis Testing Database Upgrades from Oracle Database 10g Release 2 and Newer Releases Once the SQL tuning set is transported to the SQL Performance Analyzer system you can use SQL Performance Analyzer to build a pre upgrade SQL trial by executing or generating plans of SQL statements in the SQL tuning set on the test system SQL Performance Analyzer test executes the SQL statements using a database link that you specify by connecting to the test system remotely and generating the execution plans and statistics for the SQL trial The database link should exist on the SQL Performance Analyzer system and connect to a remote user with privileges to execute the SQL tuning set on the test system After the pre upgrade SQL trial is built you need to upgrade the test system Once the database has been upgraded SQL Performance Analyzer will need to execute or generate plans of SQL statements in the SQL tuning set a second time on the upgraded test system to build a post upgrade SQL trial Alternatively if hardware resources are available you can use another upgraded test system to execute the second remote SQL trial This met
193. owing syntax wre user password server MODE value keyword value The parameters user password and server specify the username password and connection string used to connect to the replay database The parameter mode specifies the mode in which to run the wrc executable Possible values include replay the default calibrate and list_hosts The parameter keyword specifies the options to use for the execution and is dependent on the mode selected To display the possible keywords and their corresponding values run the wrc executable without any arguments The following sections describe the modes that you can select when running the wrc executable a Calibrating Replay Clients a Starting Replay Clients Displaying Host Information Calibrating Replay Clients Since one replay client can initiate multiple sessions with the database it is not necessary to start a replay client for each session that was captured The number of replay clients that need to be started depends on the number of workload streams the number of hosts and the number of replay clients for each host To estimate the number of replay clients and hosts that are required to replay a particular workload run the wrc executable in calibrate mode In calibrate mode the wrc executable accepts the following keywords xveplaydir specifies the directory that contains the preprocessed workload capture you want to replay If unspecified it defaults to the cur
194. p The Create SQL Trial page appears 2 Inthe SQL Trial Name field enter the name of the SQL trial 3 In the SQL Trial Description field enter a description of the SQL trial 4 Inthe Creation Method list determine how the SQL trial is created and what contents are generated by performing one of the following actions a Select Execute SQLs Locally The SQL trial generates both execution plans and statistics for each SQL statement in the SQL tuning set by actually running the SQL statements locally on the test system a Select Execute SQLs Remotely The SQL trial generates both execution plans and statistics for each SQL statement in the SQL tuning set by actually running the SQL statements remotely on another test system over a public database link a Select Generate Plans Locally The SQL trial invokes the optimizer to create execution plans locally on the test system without actually running the SQL statements a Select Generate Plans Remotely The SQL trial invokes the optimizer to create execution plans remotely on another test system over a public database link without actually running the SQL statements For each of these creation methods the application schema and data should already exist on the local or remote test system 5 Inthe Per SQL Time Limit list determine the time limit for SQL execution during the trial by performing one of the following actions a Select 5 minutes The execution will run each SQ
195. pa_task END This example creates and executes a SQL tuning task to tune the SQL statements that regressed in the compare performance execution named my_exec_compare of the SQL Performance Analyzer task named my_spa_task In this case it is important to use this version of the CREATE_TUNING_TASK function call Otherwise SQL statements may be tuned in the environment from the production system where they were captured which will not reflect the system change Note If you chose to execute the SQL workload remotely on a separate database you should not use this version of the CREATE TUNING_TASK function call to tune regressed SQL statements Instead you should tune any regressions identified by the SQL trials on the remote database because the application schema is not on the database running SQL Performance Analyzer Therefore you need to run SQL Tuning Advisor on the database where the schema resides and where the change was made For more information see Tuning Regressed SQL Statements From a Remote SQL Trial Using APIs on page 6 24 Table 6 1 lists the SOL Performance Analyzer parameters that can be used with the DBMS_SOLTUNE CREATE_TUNING_TASK function Table 6 1 CREATE_TUNING_TASK Function SQL Performance Analyzer Parameters Parameter Description SPA_TASK_NAME Name of the SQL Performance Analyzer task SPA_TASK_OWNER Owner of the specified SQL Performance
196. page under Real Application Testing click Database Replay The Database Replay page appears 2 Click View Workload Capture History The View Workload Capture History page appears View Workload Capture History Page Refreshed May 1 2009 12 20 21 PM PDT Refresh View Delete Export AWR Data AWR Data Select Capture Name Start SCN Duration hh mm ss Start Time Y Exported CAPTURE x090422 Completed CAPTURE1 1427095 00 15 33 May 1 2009 a 20090501115751 11 59 18 AM PDT 3 To delete a workload capture select the workload capture and click Delete This will not remove the capture files from the capture directory 4 To export AWR data for a workload capture select the workload capture and click Export AWR Data The Export AWR Data page appears click Yes 9 12 Oracle Database Real Application Testing User s Guide Capturing a Database Workload Using APIs Exporting AWR data enables detailed analysis of the workload This data is also required if you plan to run the Replay Compare Period report or the AWR Compare Period report on a pair of workload captures or replays To view details about a workload capture select the workload capture and click View The View Workload Capture page appears Under Summary information about the workload capture is displayed To view the workload profile click the Workload Profile tab Under Average Active Sessions the Active Sessions chart provides a graphic
197. pears In the Go to Task column click the icon that corresponds to the Replay Workload task The Replay Workload page appears In the Directory Object list select the directory that contains the replayed workload that you want to view After the directory is selected the Replay Workload page will be refreshed to display the Capture Summary and the Replay History sections 11 14 Oracle Database Real Application Testing User s Guide Monitoring Workload Replay Using Enterprise Manager 4 The Replay History section displays previous replays of the workload capture To view details about a replay select the replay and click View The View Workload Replay page appears 5 Under Summary information about the workload replay is displayed 6 To view the workload profile click the Workload Profile tab There are two types of charts that are available under the Workload Profile tab Elapsed Time Comparison To view this chart in the Chart Type field select Elapsed Time Comparison Chart Type Elapsed Time Comparison Capture E Replay Elapsed E Capture Elapsed Replay E Not Yet Replayed 0 1 2 3 4 5 6 Elapsed Time Minutes Network Time hh mm ss 00 00 01 Clients 1 Think Time hh mm ss 00 00 58 Clients Finished 1 The Elapsed Time Comparison chart shows how much time it has taken to replay the same workload compared to the elapsed time during the workload capture If the Replay bar is shorter tha
198. perform ongoing transactions those transactions will not be replayed properly in subsequent database replays since only that part of the transaction whose calls were executed after the workload capture is started will be replayed To avoid this problem consider restarting the database in RESTRICTED mode using STARTUP_ RESTRICTED before starting the workload capture Once the workload capture begins 9 14 Oracle Database Real Application Testing User s Guide Capturing a Database Workload Using APIs the database will automatically switch to UNRESTRICTED mode and normal operations can continue while the workload is being captured For more information about restarting the database before capturing a workload see Restarting the Database on page 9 2 To start the workload capture use the START_CAPTURE procedure BEGIN DBMS_WORKLOAD_CAPTURE START_CAPTURE name gt dec10_peak dir gt decl0 duration gt 600 capture_sts gt TRUE sts_cap_interval gt 300 END In this example a workload named dec10_peak will be captured for 600 seconds and stored in the operating system defined by the database directory object named dec10 A SQL tuning set will also be captured in parallel with the workload capture The START_CAPTURE procedure in this example uses the following parameters The name required parameter specifies the name of the workload that will be captured a The d
199. plan baselines and the SOL Tuning Advisor If the pending optimizer statistics produce satisfactory performance you can publish for use Using the Exadata Simulation Workflow The Exadata simulation workflow enables you to simulate the effects of an Exadata Storage Server installation on the performance of a SQL workload Oracle Exadata provides extremely large I O bandwidth coupled with a capability to offload SQL processing from the database to storage This allows Oracle Database to significantly reduce the volume of data sent through the I O interconnect while at the same time offloading CPU resources to the Exadata storage cells SQL Performance Analyzer can analyze the effectiveness of Exadata SQL offload processing by simulating an Exadata Storage Server installation and measuring the reduction in I O interconnect usage for the SQL workload Running the Exadata simulation does not require any hardware or configuration changes to your system After you select a SQL tuning set SQL Performance Analyzer creates a task and performs an initial trial with the Exadata Storage Server simulation disabled SQL Performance Analyzer then performs a second trial with the Exadata Storage Server simulation enabled SQL Performance Analyzer then compares the two trials using the I O Interconnect Bytes comparison metric and generates a SQL Performance Analyzer report which estimates the amount of data that would not need to be sent from the Exadata stora
200. ports are more useful than traditional HTML or text reports because they offer a similar user interface as Oracle Enterprise Manager yet they can be viewed even when the database is unavailable or even after a database is dropped Hence active reports offer the advantages of traditional reporting and dynamic Oracle Enterprise Manager analysis but eliminates the disadvantages of both Moreover active reports contain more information about the comparison analysis and provide more user interactive options It is strongly recommended that you use active reports instead of HTML or text reports The active report user interface components are very similar to those displayed in Oracle Enterprise Manager For descriptions of the user interface components see the related sections described in Reviewing the SQL Performance Analyzer Report Using Oracle Enterprise Manager on page 6 3 Tuning Regressed SQL Statements Using Oracle Enterprise Manager After reviewing the SQL Performance Analyzer report you should tune any regressed SQL statements that are identified after comparing the SQL performance If there are large numbers of SQL statements that appear to have regressed you should try to identify the root cause and make system level changes to rectify the problem In cases when only a few SQL statements have regressed consider using one of the following tuning methods to implement a point solution for them Creating SQL Plan Baselines a Running
201. quisites for Capturing a Database Workload snsssssssssssssssssrsstsstisenssestersissnsnententessesneseesne 9 1 Workload Capture Options csiis stetisse e ierta i aana aei aE E EE ieie Ea Eee 9 2 Restarting the Database issiria iiia i eiS stone 9 2 Using Filters with Workload Capture eceeseecscsnsessseeeesssssssseesesssesseeseseseseeeeseseesees 9 3 Setting Up the Capture Directory ss eresis ishn ai a i E 9 3 Workload Capture Restrictions 0 cccccceccccesssssesecesesssssesesesssssesesesesssssesesesesssesesesesessseseseseseseseseees 9 3 Enabling and Disabling the Workload Capture Feature 0 ccccceeesssessseeeeeecssssseeeeseseseeees 9 4 Capturing a Database Workload Using Enterprise Manager ccccccseesessssesssssseeseseneeeeeees 9 5 10 11 Monitoring Workload Capture Using Enterprise Manage essen eeeeeeeeees 9 10 Monitoring an Active Workload Capture ccccccccsesecceeeseeececessesnenececssesenesesesessseneseseseeenes 9 10 Stopping an Active Workload Capture ccccccsesessssssssesesesesssssesesesssssesesessssssesesesessssesesssens 9 11 Managing a Completed Workload Capture ccccccccsesssseescecesessssssenseseseenensseececeesssesnsnensneaes 9 12 Capturing a Database Workload Using APIS 000 00 cece ce ceeseseeeeeeceeesenscesesesesenesesenenenes 9 13 Defining Workload Capture Filters cccccccscssssesccceeseescscssseseececsssnseseececsssnseesecesesensnesesesenes 9 14 Starting a Wo
202. r Analyzing SQL Performance Using Oracle Enterprise Manager This section describes how to analyze SQL performance before and after the system change using Oracle Enterprise Manager To analyze SQL performance using Enterprise Manager 1 On the Guided Workflow page click the Execute icon for Compare Step 2 and Step 3 The Run SQL Trial Comparison page appears Run SQL Trial Comparison Cancel Submit Task Name IMMCHAN SPA_GUIDED_WORKFLOW Compare trials to assess change impact SQL Tuning Set IMMCHAN STS_CURSOR_CACHE SQL Performance Analyzer trial comparison allows you to assess the impact on SQL Tuning Set performance of Trial 1 Name SQL_TRIAL_1241213421833 M changes made between two trials Description It is important to know the difference between Trial 1 and Trial 2 execution environments in order to properly assign impacts to the changes between trials Tracking environmental changes between trials is currently a user SQL Executed Yes Trial 2 Name SQL_TRIAL_1241213881923 responsibility Denmiption The selected comparison metric is used as the basis for SQL Executed Yes comparison and defaults to execute elapsed time when both trials contain test execution statistics When execution Comparison Metric Elapsed Time x statistics are not available a less accurate comparison can be made using optimizer cost Schedule Time Zone Pacific Pago_Pago x Immediately O Later Date May
203. r This section describes how to preprocess a captured workload using Enterprise Manager The primary tool for preprocessing workload captures is Oracle Enterprise Manager If for some reason Oracle Enterprise Manager is unavailable you can preprocess Preprocessing a Database Workload 10 1 Preprocessing a Database Workload Using Enterprise Manager workload captures using the APIs as described in Preprocessing a Database Workload Using APIs on page 10 4 To preprocess a captured workload using Enterprise Manager 1 On the Software and Support page under Real Application Testing click Database Replay The Database Replay page appears 2 Inthe Go to Task column click the icon that corresponds to the Preprocess Captured Workload task The Preprocess Captured Workload page appears Preprocess Captured Workload Cancel Preprocess Workload Directory Select a directory object that contains a captured workload TIP If the capture was done on a cluster database and a shared capture directory was not used copy the contents of the capture directories from all database instances into a single directory and then select the directory Directory Object Create Directory Object 3 Inthe Directory Object list select a directory that contains the captured workload that you want to preprocess After a directory is selected the Preprocess Captured Workload page will be refreshed to display the Capture
204. r task Instead a reference to the SQL tuning set is recorded in association to the new SQL trial which in this example is first trial Create a second SQL trial and associate it to the second SQL tuning second to which you want to compare EXEC DBMS SQLPA EXECUTE_ANALYSIS_TASK task_name gt aname execution_type gt convert sqlset execution_name gt second trial execution_params gt DBMS _ADVISOR ARGLIST sqlset_name my_second_sts sqlset_owner APPS Compare the performance data from the two SQL trials or SQL tuning sets by running a comparison analysis EXEC DBMS SQLPA EXECUTE_ANALYSIS_TASK task_name gt aname execution_type gt compare execution_name gt comparison execution_params gt DBMS _ADVISOR ARGLIST workload_impact_threshold 0 sql_impact_threshold 0 In this example the workload and per SQL impact threshold are set to 0 for comparison the default value is 1 After the comparison analysis is complete generate a SOL Performance Analyzer report using the DBMS_SQLPA REPORT_ANALYSIS_TASK function For information about generating a SQL Performance Analyzer report using APIs see Analyzing SQL Performance Using APIs on page 6 10 Once the report is generated review it to identify any differences between the contents of the two SQL tuning sets Example 6 8 shows the Analysis Information and Report Summary sections of a sample rep
205. r test you can use either one to perform your testing Note The use of SQL Performance Analyzer and Database Replay requires the Oracle Real Application Testing licensing option For more information see Oracle Database Licensing Information SQL Performance Analyzer System changes such as a upgrading a database or adding an index may cause changes to execution plans of SQL statements resulting in a significant impact on SQL performance In some cases the system changes may cause SQL statements to regress resulting in performance degradation In other cases the system changes may improve SQL performance Being able to accurately forecast the potential impact of system changes on SQL performance enables you to tune the system beforehand in cases where the SQL statements regress or to validate and measure the performance gain in cases where the performance of the SQL statements improves SQL Performance Analyzer automates the process of assessing the overall effect of a change on the full SQL workload by identifying performance divergence for each SQL statement A report that shows the net impact on the workload performance due to the change is provided For regressed SQL statements SOL Performance Analyzer also provides appropriate executions plan details along with tuning recommendations As a result you can remedy any negative outcome before the end users are affected Furthermore you can validate with significant ti
206. r test execute of SQL statements in the SQL tuning set To do so call the EX ECUTE_ANALYSIS_TASK procedure using the following parameters Set the task_name parameter to the name of the SQL Performance Analyzer task that you want to execute Set the execution_type parameter to EXPLAIN PLAN or TEST EXECUTE 7 14 Oracle Database Real Application Testing User s Guide Tuning Regressed SQL Statements After Testing a Database Upgrade If you choose to use EXPLAIN PLAN only execution plans will be generated Subsequent comparisons will only be able to yield a list of changed plans without making any conclusions about performance changes If you choose to use TEST EXECUTE the SQL workload will be executed to completion This effectively builds the pre upgrade SQL trial using the statistics and execution plans generated from the test system Using TEST EXECUTE is recommended to capture the SQL execution plans and performance data at the source thereby resulting in a more accurate analysis Specify a name to identify the execution using the execution_name parameter If not specified then SQL Performance Analyzer automatically generates a name for the task execution a Set the DATABASE_LINK task parameter to the global name of a public database link connecting to a user with the EXECUTE privilege for the DBMS_SQLPA package and the ADVISOR privilege on the test
207. re files will be stored Once workload capture begins all external database calls are written to the capture files The capture files contain all relevant information about the client request such as SQL 8 2 Oracle Database Real Application Testing User s Guide Analysis and Reporting text bind values and transaction information Background activities and database scheduler jobs are not captured These capture files are platform independent and can be transported to another system See Also a Chapter 9 Capturing a Database Workload for information about how to capture a workload on the production system Workload Preprocessing Once the workload has been captured the information in the capture files need to be preprocessed Preprocessing creates all necessary metadata needed for replaying the workload This must be done once for every captured workload before they can be replayed After the captured workload is preprocessed it can be replayed repeatedly on a replay system running the same version of Oracle Database Typically the capture files should be copied to another system for preprocessing As workload preprocessing can be time consuming and resource intensive it is recommended that this step be performed on the test system where the workload will be replayed See Also a Chapter 10 Preprocessing a Database Workload for information about how to preprocess a captured workload Workload Replay After a captured wo
208. rent directory Replaying a Database Workload 11 5 Steps for Replaying a Database Workload a process_per_cpu specifies the maximum number of client processes that can run per CPU The default value is 4 a threads_per_process specifies the maximum number of threads that can run within a client process The default value is 50 The following example shows how to run the wrc executable in calibrate mode gt wrc mode calibrate replaydir replay In this example the wrc executable is executed to estimate the number of replay clients and hosts that are required to replay the workload capture stored in a subdirectory named replay under the current directory In the following sample output the recommendation is to use at least 21 replay clients divided among 6 CPUs Workload Replay Client Release 11 2 0 0 2 Production on Fri May 1 13 06 33 2009 Copyright c 1982 2009 Oracle All rights reserved Report for Workload in oracle replay Recommendation Consider using at least 21 clients divided among 6 CPU s Workload Characteristics max concurrency 1004 sessions total number of sessions 1013 Assumptions 1 client process per 50 concurrent sessions 4 client process per CPU think time scale 100 connect time scale 100 synchronization TRUE Starting Replay Clients After determining the number of replay clients that are needed to replay the workload you need to start the replay clients by
209. rformance analysis into a SQL tuning set on the production system then transport it to the test system where the performance analysis will be performed as described in Capturing the SQL Workload on page 2 3 Creating an Analysis Task Using Enterprise Manager There are several workflows available in Oracle Enterprise Manager for creating a SQL Performance Analyzer task Creating an Analysis Task 3 1 Creating an Analysis Task Using Enterprise Manager To create an analysis task using Enterprise Manager 1 On the Software and Support page under Real Application Testing click SOL Performance Analyzer The SQL Performance Analyzer page appears SQL Performance Analyzer Page Refreshed May 10 2010 5 58 35 AM PDT Refresh View Data Real Time 15 Second Refresh SQL Performance Analyzer allows you to test and to analyze the effects of changes on the execution performance of SQL contained in a SQL Tuning Set SQL Performance Analyzer Workflows Create and execute SQL Performance Analyzer Task experiments of different types using the following links Upgrade from 9i or 10 1 Test and analyze the effects of database upgrade from 9i or 10 1 on SQL Tuning Set performance Upgrade from 10 2 or 11g Test and analyze the effects of database upgrade from 10 2 or 11g on SQL Tuning Set performance Parameter Change Test and compare an initialization parameter change on SQL Tuning Set performance Optimizer Statistics Test and analy
210. rformance data by executing the SQL statements stored in the SQL tuning set as described in Chapter 4 Creating a Pre Change SQL Trial Creating an Analysis Task Using APIs This section describes how to create a SQL Performance Analyzer task by using the DBMS_SQLPA CREATE_ANALYSIS_TASK function A task is a database container for SQL Performance Analyzer execution inputs and results Tip Before proceeding capture the SQL workload to be used in the performance analysis into a SQL tuning set on the production system then transport it to the test system where the performance analysis will be performed as described in Capturing the SQL Workload on page 2 3 Call the CREATE_ANALYSIS_TASK function to prepare the analysis of a SQL tuning set using the following parameters a Set task_name to specify an optional name for the SQL Performance Analyzer task Set sqlset_name to the name of the SQL tuning set a Set sqlset_owner to the owner of the SQL tuning set The default is the current schema owner Creating an Analysis Task 3 13 Creating an Analysis Task Using APIs a Set basic_filter to the SQL predicate used to filter the SQL from the SQL tuning set Set order_by to specify the order in which the SQL statements will be executed You can use this parameter to ensure that the more important SQL statements will be processed and not skipped if the time limit is reached a Set top_sql to c
211. rformance data is built you can compare the pre change version of performance data to the post change version Run a comparison analysis using the 1 D BMS _ SQLPA EXECUTE_ANALYSTS_TASK procedure or function To compare the pre change and post change SQL performance data 1 Call the EXECUTE_ANALYSIS_TASK procedure or function using the following parameters Set the task_name parameter to the name of the SQL Performance Analyzer task Set the execution_type parameter to COMPARE PERFORMANCE This setting will analyze and compare two versions of SQL performance data Specify a name to identify the execution using the execution_name parameter If not specified it will be generated by SQL Performance Analyzer and returned by the function Specify two versions of SQL performance data using the execution_params parameters The execution_params parameters are specified as name value pairs for the specified execution Set the execution parameters that are related to comparing and analyzing SQL performance data as follows Set the execution_name1 parameter to the name of the first execution before the system change was made This value should correspond to the value of the execution_name parameter specified in Creating a Pre Change SQL Trial Using APIs on page 4 4 Set the execution_name2 parameter to the name of the second execution after the system change was made This v
212. rkload replay after change for which the reported will be generated This parameter is required The replay_id2 parameter specifies the numerical identifier of the workload replay after change for which the reported will be generated If unspecified the comparison will be performed with the workload capture The format parameter specifies the report format Valid values include DBMS_ WORKLOAD_CAPTURE TYPE_HTML for HTML DBMS_WORKLOAD_CAPTURE TYPE XML for XML and DBMS_WORKLOAD_CAPTURE TYPE_TEXT for text This parameter is required a The result parameter specifies the output of the report For information about how to interpret the SQL Performance Analyzer report see Reviewing the SQL Performance Analyzer Report Using APIs on page 6 12 See Also a Oracle Database PL SQL Packages and Types Reference for information about the DBMS_WORKLOAD_REPLAY package Reviewing Replay Compare Period Reports You can use replay compare period reports to perform a high level comparison of one workload replay to its capture or to another replay of the same capture The replay compare period report contains a summary of the most important changes between the two runs By reviewing this report you can determine if any replay divergence occurred and whether there were any significant performance changes You can then use this information to determine the appropriate action to take such as re
213. rkload Capture 0 ccsssessesecesssssssesesessesesescsesssesesescsssesesesescssseseecscsssnsnesesenes 9 14 Stopping a Workload Captures na d eona ea oee Eais so ERSAT inet 9 15 Exporting AWR Data for Workload Capture sssssssssssessessssiesissesssssinsiesesstnniesenstesensnenteneeneess 9 16 Monitoring Workload Capture Using Views cccccc ccc ce ceeseseeceeecesesenenesessesseneseseseenes 9 16 Preprocessing a Database Workload Preprocessing a Database Workload Using Enterprise Managet 0 cccccseccsseseseseeeseees 10 1 Preprocessing a Database Workload Using APIS 0 0 0 0 ce cseeeeee cece eeeeeeneneseseeeneneseneseenes 10 4 Running the Workload Analyzer Command Line Interface ccccecccece cece eeeeeees 10 5 Replaying a Database Workload Setting Up the Test System ninpis enini e e Et E EE E e R R E LL 11 1 Restoring the Databas ssentione gonnen e E E E eestor tes 11 1 Resetting the Systemi TMe iin e eree e a a E e aE eieae 11 2 Steps for Replaying a Database Workload s ssssssssisssssssssstsstestissnssentessisensnentensissesnenrensrssesses 11 2 Setting Up the Replay Directory sesisih perenah aar ERa a ees Ee EE EERS rE n Ser EEE Eiaeai 11 2 Resolving References to External Systems cccccesssesssssesesescseesesesesesssesesesescssseseececsssnseececeees 11 2 Remapping Connections cccccccesseessssescscnssessssesesssseesecseneessesesessssesescsseecessesesesseecesseneeesesesseatees 11 3 Specifying
214. rkload has been preprocessed it can be replayed on a test system During the workload replay phase Oracle Database performs the actions recorded during the workload capture phase on the test system by re creating all captured external client requests with the same timing concurrency and transaction dependencies of the production system Database Replay uses a client program called the replay client to re create all external client requests recorded during workload capture Depending on the captured workload you may need one or more replay clients to properly replay the workload A calibration tool is provided to help determine the number of replay clients needed for a particular workload Because the entire workload is replayed including DML and SQL queries the data in the replay system should be as logically similar to the data in the capture system as possible This will minimize replay divergence and enable a more reliable analysis of the replay See Also a Chapter 11 Replaying a Database Workload for information about how to replay a preprocessed workload on the test system Analysis and Reporting Once the workload is replayed in depth reporting is provided for you to perform detailed analysis of both workload capture and replay The workload capture report and workload replay report provide basic information about the workload capture and replay such as errors encountered during replay and data divergence in rows returned by
215. rocess and the directory object and path Analyzing Replayed Workload 12 5 Using Compare Period Reports a Replay options selected for the workload replay and the number of replay clients that were started a Overall statistics about the workload replay and the workload capture such as the total DB time captured and replayed and the number of logins and transactions captured and replay and the corresponding percentages with respect to total system activity a Profile of the replayed workload a Replay divergence a Error divergence a DML and SQL query data divergence Using Compare Period Reports Compare period reports enable you to compare one workload replay to its capture or to another replay of the same capture The following sections describe how to generate and review the various types of compare period reports Generating Compare Period Reports Using Enterprise Manager Generating Compare Period Reports Using APIs Reviewing Replay Compare Period Reports Generating Compare Period Reports Using Enterprise Manager This section describes how to generate compare period reports using Oracle Enterprise Manager The primary tool for generating compare period reports is Oracle Enterprise Manager If for some reason Oracle Enterprise Manager is unavailable you can generate compare period reports using APIs as described in Generating Compare Period Reports Using APIs on page 12 7 To generate compare period repo
216. rprise Manager enables you to run Workload Analyzer as part of the workload preprocessing Workload Analyzer is composed of two JAR files doranalyzer jar and dbrparser jar located in the SORACLE_HOME rdbms j1ib directory of a system running Oracle Database Enterprise Edition Release 11 2 0 2 or higher Workload Analyzer requires Java 1 5 or higher and the ojdbc5 jar file located in the SORACLE_HOME jdbc 1ib directory To run Workload Analyzer in the command line interface run the following java command on a single line java classpath SORACLE_HOME jdbc 1lib ojdbc5 jar SORACLE_HOME rdbms jlib dbrparser jar SORACLE_HOME rdbms j1lib dbranalyzer jar oracle dbreplay workload checker CaptureChecker lt capture_directory gt lt connection_string gt For the capture_directory parameter input the operating system path of the capture directory This directory should also contain the exported AWR data for the workload capture For the connection_string parameter input the connection string of an Oracle database that is release 11 1 or higher The Workload Analyzer program will then prompt you to input the username and password of a database user with EXECUTE privileges for the DBMS_WORKLOAD CAPTURE package and the SELECT_CATALOG role on the target database An example of this command may be java classpath SORACLE_HOME jdbc 1lib ojdbc5 jar SORACLE_HOME rdbms jlib dbrparser
217. rts using Enterprise Manager 1 On the Software and Support page under Real Application Testing click Database Replay The Database Replay page appears 2 Inthe Go to Task column click the icon that corresponds to the Replay Workload task The Replay Workload page appears 3 In the Directory Object list select the directory that contains the replayed workload for which you want to generate a compare period report After the directory is selected the Replay Workload page will be refreshed to display the Capture Summary and the Replay History sections 4 The Replay History section displays previous replays of the workload capture Select the replay for which you want to generate a compare period report and click View The View Workload Replay page appears 5 Click the Report tab 12 6 Oracle Database Real Application Testing User s Guide Using Compare Period Reports 6 Under Compare Period Report select the first and second workload captures or replays you want to compare Compare Period Report First Workload Capture or Replay CAPTURE x112 20100509051233 May 9 2010 5 13 20 AM Second Workload Capture or Replay REPLAY x112 20100510053350 May 10 2010 5 37 42 AM Run Replay Compare Period Report Run AWR Compare Period Report Run SQL Performance Analyzer Report 7 To generate a Replay Compare Period report click Run Replay Compare Period Report Use the replay co
218. s set to OBJECT_ID all replay actions will be executed only after all relevant COMMIT actions have completed Relevant COMMIT actions must meet the following criteria m Issued before the given action in the workload capture a Modified at least one of the database objects for which the given action is referencing either implicitly or explicitly Setting this parameter to OBJECT_ID allows for more concurrency during workload replays for COMMIT actions that do not reference the same database objects during workload capture You can disable this option by setting the parameter to OFF but the replay will likely yield significant replay divergence However this may be desirable if the workload consists primarily of independent transactions and divergence during unsynchronized replay is acceptable Controlling Session Connection Rate The connect_time_scale parameter enables you to scale the elapsed time between the time when the workload capture began and each session connects You can use this option to manipulate the session connect time during replay with a given percentage value The default value is 100 which will attempt to connect all sessions as captured Setting this parameter to 0 will attempt to connect all sessions immediately Controlling Request Rate Within a Session User think time is the elapsed time while the replayed user waits between issuing calls within a single session To control replay speed
219. s the impact of the change including undesired results new contention points or plan regressions Extensive analysis and reporting is provided to help identify any potential problems such as new errors encountered and performance divergence Database Replay performs workload capture of external client workload at the database level and has negligible performance overhead Capturing the production workload eliminates the need to develop simulation workloads or scripts resulting in significant cost reduction and time savings By using Database Replay realistic testing of complex applications that previously took months using load simulation tools can now be completed in days This enables you to rapidly test changes and adopt new technologies with a higher degree of confidence and at lower risk You can use Database Replay to test any significant system changes including Database and operating system upgrades Configuration changes such as conversion of a database from a single instance to an Oracle Real Application Clusters Oracle RAC environment a Storage network and interconnect changes Operating system and hardware migrations See Also a Part II Database Replay for information about using Database Replay 1 2 Oracle Database Real Application Testing User s Guide Part SQL Performance Analyzer SQL Performance Analyzer enables you to assess the impact of system changes on the response time of SQL stateme
220. s to fix the root cause of the problem To run SQL Tuning Advisor 1 On the SQL Performance Analyzer Task Result page under Recommendations click Run SQL Tuning Advisor The Schedule SQL Tuning Task page appears 2 Inthe Tuning Task Name field enter a name for the SQL tuning task 3 Inthe Tuning Task Description field optionally enter a name for the SQL tuning task 4 Under Schedule select a Immediately to start the job now a Later to schedule the job to start at a time specified using the Time Zone Date and Time fields 5 Click OK The SQL Performance Analyzer Task Result page appears A link to the SQL tuning report appears under Recommendations 6 To view the SQL tuning report click the SQL Tune Report link The SQL Tuning Results page appears Comparing SQL Trials 6 9 Comparing SQL Trials Using APIs See Also Oracle Database 2 Day Performance Tuning Guide for information about running the SQL Tuning Advisor Comparing SQL Trials Using APIs Comparing SQL trials using APIs involves the following steps Analyzing SQL Performance Using APIs Reviewing the SQL Performance Analyzer Report Using APIs Comparing SQL Tuning Sets Using APIs Tuning Regressed SQL Statements Using APIs Tuning Regressed SQL Statements From a Remote SQL Trial Using APIs Creating SQL Plan Baselines Using APIs Using SQL Performance Analyzer Views Analyzing SQL Performance Using APIs After the post change SQL pe
221. ses the runtime statistics captured in the SQL tuning sets to perform its comparison analysis and reports on any new or missing SQL statements that are found in one SQL tuning set but not in the other Any changes in execution plans between the two SQL tuning sets are also reported For each SQL statement in both SQL tuning sets improvement and Comparing SQL Trials 6 17 Comparing SQL Trials Using APIs regression findings are reported for each SQL statement calculated based on the average statistic value per execution and for the entire workload calculated based on the cumulative statistic value To compare SQL tuning sets using the DBMS_SQULPA package 1 Create a SQL Performance Analyzer task VAR aname varchar2 30 EXEC aname compare_s2s EXEC aname DBMS SQLPA CREATE_ANALYSIS_TASK task_name gt aname It is not necessary to associate a SQL tuning set to the task during creation Create the first SQL trial and convert the first SQL tuning set EXEC DBMS SQLPA EXECUTE_ANALYSIS_TASK task_name gt aname execution_type gt convert sqlset execution_name gt first trial execution_params gt DBMS _ADVISOR ARGLIST sqlset_name my_first_sts sqlset_owner APPS Specify the name and owner of the SQL tuning set using the SQLSET_NAME and SQLSET_OWNER task parameters The content of the SQL tuning set will not be duplicated by the SQL Performance Analyze
222. should match the execut ion_name parameter of the execution for which you want to generate a report To generate a report to display the results of Execution plans generated for the SQL workload set this value to match the execution_name parameter of the desired EXPLAIN PLAN execution Execution plans and execution statistics generated for the SQL workload set this parameter to match the value of the execution_name parameter used in the desired TEST EXECUTE execution A comparison analysis set this value to match the execution_name parameter of the desired ANALYZE PERFORMANCE execution If unspecified SOL Performance Analyzer generates a report for the last execution Set the type parameter to specify the type of report to generate Possible values include TEXT default HTML XML and ACTIVE Active reports provides in depth reporting using an interactive user interface that enables you to perform detailed analysis even when disconnected from the database or Oracle Enterprise Manager It is recommended that you use active reports instead of HTML or text reports when possible For information about active reports see About SQL Performance Analyzer Active Reports on page 6 7 Set the level parameter to specify the format of the recommendations Possible values include TYPICAL default ALL BASIC CHANGED CHANGE PLANS ERRORS IMPROVED REGRESSED TIMEOUT UNCHANGED UNCHANGED_PLANS and UNSUPPORTED
223. ss Captured Workload Database Version Database x112 Cancel Step 1 of 3 Next Version 11 2 0 2 0 Capture Name CAPTURE x112 20100726181024 Logged In As IMM HAN The current database version is 11 2 0 2 0 Continue only if you intend to replay the captured workload on a database of the same version y Advanced Run the Workload Analyzer to find potential replay problems in the captured workload Recommended 5 Ensure that the current database version displayed matches the database version on the intended replay system Preprocessing must be performed on a system that is running the same version of Oracle Database as the replay system Under Advanced select whether to run the Workload Analyzer Workload Analyzer analyzes a workload capture directory and identifies parts of a captured workload that may not replay accurately due to insufficient data errors that occurred during workload capture or usage features that are not supported by Database Replay The results of the workload analysis are saved to an HTML report named wcr_cap_analysis html located in the capture directory that is being analyzed If an error can be prevented the workload analysis report displays available preventive actions that can be implemented before replay If an error cannot be corrected the workload analysis report provides a description of the error so it can be accounted for during replay This option is enabled by default if the Workload Analyzer
224. ssseseseseesesssssseesecesesssssesssessessesesesesseeeees 2 4 Measuring the Pre Change SQL Performance cccccscccssesesesescseeesescscsesesesescsesesesesesessseseseeeee 2 5 Making a System Changes iaie iinan anaana aiy 2 7 Measuring the Post Change SQL Performance ss ssssssssiersiseessestertessessestentisresnesnentesresnesseneennens 2 7 Comparing Performance Measurements cccccccesesessecssssseseesesssssseesesesssssssesssesssseesesesssseeeees 2 7 Fixing Regressed SQL Statements arrea rnai e oss oien eae eiee ainese epe rE S oriai ESTA 2 8 Creating an Analysis Task Creating an Analysis Task Using Enterprise Manager esse ssssssssssisrsissrssestsrressisnerienressesnesseene 3 1 Using the Parameter Change Workflow cccccsessscssssssesesescsessnesesescsesesesesescssssseseecsssesesnesseesen 3 3 Using the Optimizer Statistics WOrkflOW c cece cesssssesesesessesesescsssesesesescsesesesescseseseseseecenens 3 6 Using the Exadata Simulation Workflow cccsecccssssesesescsesesesescseesesescsesesesesescsesesesesesessseseseecees 3 9 Using the Guided Workflow sssrinin aeaiee iredi duia 3 12 Creating an Analysis Task Using APIS ccc cece ce cseseseseecesesseseesesesesseenesesesesenenesesesenenes 3 13 Running the Exadata Simulation Using APIs 0 ccccssssesesssssssssesescsesesesesescsssesesescscsnsneseesees 3 14 Creating a Pre Change SQL Trial Creating a Pre Change SQL Trial Using Enterprise Man
225. statistic to obtain more details as described in Reviewing the SQL Performance Analyzer Report Global Statistics Details on page 6 7 In this example the improvement impact is 20 while the regression impact is 2 so the overall impact of the system change is an improvement of approximately 18 This means that if all regressions are fixed in this example the overall impact of the change will be an improvement of 20 Note The overall impact percentage may sometimes be off by 1 compared to the sum of the improvement impact and the regression impact This discrepancy may be caused by rounding or if the SQL and workload time limits are set at 1 which is the recommended value This enables the analysis to focus on SQL statements with higher impact by filtering out those that have a minimal impact 2 Review the chart in the SOL Statement Count subsection The x axis of the chart shows the number of SQL statements whose performance improved regressed or remain unchanged after the system change The y axis shows the number of SQL statements The chart also indicates whether the explain plans changed for the SQL statements SQL Statement Count 1 200 800 400 0 SQL Count Improved Regressed Unchanged Change in Elapsed Time New Plan J Same Plan L This chart enables you to quickly weigh the relative performance of the SQL statements You can click any bar in the chart to obtain more de
226. sts Remapping Connections During workload capture connection strings used to connect to the production system are captured In order for the replay to succeed you need to remap these connection strings to the replay system The replay clients can then connect to the replay system using the remapped connections For Oracle Real Application Clusters Oracle RAC databases you can map all connection strings to a load balancing connection string This is especially useful if the number of nodes on the replay system is different from the capture system Alternatively if you want to direct workload to specific instances you can use services or explicitly specify the instance identifier in the remapped connection strings Specifying Replay Options After the database is restored and connections are remapped you can set the following replay options as appropriate a Preserving COMMIT Order a Controlling Session Connection Rate Controlling Request Rate Within a Session Preserving COMMIT Order The synchronization parameter controls whether the COMMIT order in the captured workload will be preserved during replay If this parameter is set to SCN the COMMIT order in the captured workload will be preserved during replay and all replay actions will be executed only after all dependent COMMIT actions have completed Replaying a Database Workload 11 3 Steps for Replaying a Database Workload If this parameter i
227. t you will need to set up a separate SQL Performance Analyzer system running Oracle Database 11g Release 2 You will be using this system to run SQL Performance Analyzer Neither your production data or schema need to be available on this system since the SQL tuning set will be built using statistics stored in the SQL trace files from the production system SQL Performance Analyzer tasks will be executed remotely on the test system to generate the execution plan and statistics for the SQL trial over a database link that you specify The database link must be a public database link that connects to a user with the EXECUTE privilege for the DBMS_SQLPA package and the ADVISOR privilege on the test system You should also drop any existing PLAN_ TABLE from the user s schema on the test system Once the upgrade environment is configured as described perform the steps as described in the following procedure to use SQL Performance Analyzer in a database upgrade from Oracle Database 10g Release 2 or a newer release to any later release 1 On the production system capture the SQL workload that you intend to analyze and store it in a SQL tuning set as described in Capturing the SQL Workload on page 2 3 2 Set up the test system so that it matches the production environment as closely as possible as described in Setting Up the Test System on page 2 4 3 Transport the SQL tuning set to the SQL Performance Analyz
228. t field 4 Inthe Description field optionally enter a description of the task 5 Inthe Creation Method list determine how the SQL trial is created and what contents are generated by performing one of the following actions a Select Execute SQLs The SQL trial generates both execution plans and statistics for each SQL statement in the SQL tuning set by actually running the SQL statements Select Generate Plans The SQL trial invokes the optimizer to create execution plans only without actually running the SQL statements 6 Inthe Per SQL Time Limit list determine the time limit for SQL execution during the trial by performing one of the following actions a Select 5 minutes The execution will run each SQL statement in the SQL tuning set up to 5 minutes and gather performance data a Select Unlimited The execution will run each SQL statement in the SQL tuning set to completion and gather performance data Collecting execution statistics provides greater accuracy in the performance analysis but takes a longer time Using this setting is not recommended because the task may be stalled by one SQL statement for a prolonged time period a Select Customize and enter the specified number of seconds minutes or hours 7 Inthe Parameter Change section complete the following steps a Inthe Parameter Name field enter the name of the initialization parameter whose value you want to modify or click the Search icon to select
229. tails about the SQL statements as described in Reviewing the SQL Performance Analyzer Report Global Statistics Details on page 6 7 Only up to the top 100 SQL statements will be displayed even if the actual number of SQL statements exceeds 100 In this example all SQL statements were unchanged after the system change 6 6 Oracle Database Real Application Testing User s Guide Comparing SQL Trials Using Oracle Enterprise Manager Reviewing the SQL Performance Analyzer Report Global Statistics Details You can use the SQL Performance Analyzer Report to obtain detailed statistics for the SQL workload comparison The details chart enables you to drill down into the performance of SQL statements that appears in the report Use the information in this section to investigate why the performance of a particular SQL statement regressed Note The report displays only up to the top 100 SQL statements even if the actual number of SQL statements exceeds 100 To review global statistics details 1 Inthe Projected Workload Elapsed Time subsection click the impact percentage of the SQL statements for which you want to view details To view SQL statements whose performance Improved click the percentage for Improvement Impact a Regressed click the percentage for Regression Impact Improved or regressed click the percentage for Overall Impact A table including the detailed statistics appears Depending on the type of SQL st
230. tement or execution plan Example 6 4 shows an example of the Errors subsection of a SQL Performance Analyzer report Example 6 4 Errors 47bjmcdtw6 htn ORA 00942 table or view does not exist br6lbjp4tnf7y ORA 00920 invalid relational operator Result Details The Result Details section represents a drill down into the performance of SQL statements that appears in the Result Summary section of the report Use the information in this section to investigate why the performance of a particular SQL statement regressed This section will contain an entry of every SQL statement processed in the SQL performance impact analysis Each entry is organized into the following subsections a SQL Details a Execution Statistics a Execution Plans SQL Details This section of the report summarizes the SQL statement listing its information and execution details Example 6 5 shows the SQL Details subsection of a sample report Example 6 5 SQL Details SQL Details Object ID 204 Schema Name APPS SQL ID 2wtgxbjz6u2by Execution Frequency 1 SQL Text SELECT my_query_14_scott ORDERED INDEX t1 USE_HASH t1 B t2 pg_featurevalue_05_id pg_featurevalue_05_id r t4 elementrange_id pg_featurevalue_15_id G t5 elementgroup_id pg_featurevalue_01_id r t6 elementrange_id In Example 6 5 the report summarizes the regressed SQL statement whose ID is 2wtgxbj z6u2by and corresponding object ID is 204 C
231. terest you can generate a report for the SQL statement to perform more detailed investigation For example you may want to investigate the SQL statement with the sql_id value of 7gj3w9ya4d9sj and object_ id value of 4 because it has the highest impact on the workload SELECT DBMS_SQLPA REPORT_ANALYSIS_TASK task_name gt aname object_id gt 4 rep FROM dual Example 6 10 shows a sample report generated for this SQL statement Example 6 10 Sample Report for SQL Statement SQL Details Object ID 4 SQL ID Tgj3w9ya4d9sj SQL Text my_csts_queryl select FROM emp where empno 2 SQL Execution Statistics average Impact on Value Value Impact Stat Name Workload Before After on SQL elapsed_time 41 04 036945 001849 95 cpu_time 13 74 004772 00185 61 24 buffer_gets 9 59 8 2 69 01 cost 11 76 1 l 10 reads 4 08 0 0 63 33 writes 0 0 0 0 rows 0 0 executions 22 20 6 20 Oracle Database Real Application Testing User s Guide Comparing SQL Trials Using APIs plan_count 1 The performance of this SQL has improved 2 The structure of the SQL execution plan has changed Plan Execution Statistics average Statistic Name Plans Before Change Plans After Change plan hash value 440231712 571903972 3634526668 571903972 3634526668 schema name APPS1 APPS2 APPS2 APPS2 APPS2 executions 7 5 10 10 10 cost 2 1 2 i 2 elapsed_time 108429 000937 00491 000503
232. the corresponding attribute on which the filter will be applied It is possible to use wildcards such as with some of the attributes such as modules and actions To remove filters from a workload capture use the DELETE_FILTER procedure BEGIN DBMS_WORKLOAD_CAPTURE DELETE FILTER fname gt user_ichan END In this example the DELETE_FILTER procedure removes the filter named user_ichan from the workload capture The DELETE_FILTER procedure in this example uses the fname required parameter which specifies the name of the filter to be removed The DELETE_FILTER procedure will not remove filters that belong to completed captures it only applies to filters of captures that have yet to start Starting a Workload Capture Before starting a workload capture you must first complete the prerequisites for capturing a database workload as described in Prerequisites for Capturing a Database Workload on page 9 1 You should also review the workload capture options as described in Workload Capture Options on page 9 2 It is important to have a well defined starting point for the workload so that the replay system can be restored to that point before initiating a replay of the captured workload To have a well defined starting point for the workload capture it is preferable not to have any active user sessions when starting a workload capture If active sessions
233. the following parameters a The synchronization required parameter determines if synchronization will be used during workload replay If this parameter is set to SCN the COMMIT order in the captured workload will be preserved during replay and all replay actions will be executed only after all dependent COMMIT actions have completed The default value is SCN If this parameter is set to OBJECT_ID all replay actions will be executed only after all relevant COMMIT actions have completed Relevant COMMIT actions must meet the following criteria Issued before the given action in the workload capture Modified at least one of the database objects for which the given action is referencing either implicitly or explicitly Setting this parameter to OBJECT_ID allows for more concurrency during workload replays for COMMIT actions that do not reference the same database objects during workload capture You can disable this option by setting the parameter to OFF but the replay will likely yield significant replay divergence However this may be desirable if the workload consists primarily of independent transactions and divergence during unsynchronized replay is acceptable The connect_time_scale parameter scales the elapsed time from when the workload capture started to when the session connects with the specified value and is interpreted as a value Use this parameter to increase or decrease the n
234. the replay database Z TIP Connections must point to the replay database for a successful replay Use a single connect descriptor for all client connections Test Connection DESCRIPTION ADDRESS_LIST ADDRESS PROTOCOL TCP HOST dadvmn0672 us oracle com PORT 25170 CONNECT_DATA SID x090422 Ouse a single TNS net service name for all client connections TIP All Replay Clients must be able to resolve the net service name for example through a local tnsnames ora file Use a separate connect descriptor or net service name for each client connect descriptor captured in the workload 11 Remap captured connection strings to connection strings that point to the replay system Click the Connection Mappings tab There are several methods you can use to remap captured connection strings You can choose to a Use a single connect descriptor for all client connections by selecting this option and entering the connect descriptor you want to use The connect descriptor should point to the replay system To test the connection click Test Connection If the connect descriptor is valid an Information message is displayed to inform you that the connection was successful 11 10 Oracle Database Real Application Testing User s Guide Replaying a Database Workload Using Enterprise Manager Usea single TNS net service name for all client connections by selecting this option and entering the net service name
235. the system change ensure that you have executed the SQL workload in the initial environment to generate the pre change performance data For example if you are testing how changing a database initialization parameter will affect SQL performance execute the SQL workload once before changing the database initialization parameter to a new value Depending on the type of change you are making it may be necessary to reconfigure the environment on the test system to match the new environment for which you want to perform SQL performance analysis For more information see Making a System Change on page 2 7 Note You can optionally run SQL trials on a remote system by providing access to a public database link When conducting remote SQL trials the database version of the remote database where the SQL statements are executed must be less than or equal to the database version of the database to which it connects Starting with Oracle Database release 11 2 0 2 the remote database can be a read only database such as an Oracle Active Data Guard instance SQL Performance Analyzer on page 1 1 lists examples of possible system changes that can be analyzed using SQL Performance Analyzer For example you may want to determine how a database initialization parameter change or database upgrade will affect SQL performance You may also decide to change the system based on recommendations from an advisor such as Automatic Database Diagnostic Monit
236. to Store the SQL text and any necessary auxiliary information in a single persistent database object a Populate update delete and select captured SQL statements in the SQL tuning set Introduction to SQL Performance Analyzer 2 3 Setting Up the Test System Load and merge content from various data sources such as the Automatic Workload Repository AWR or the cursor cache a Export the SQL tuning set from the system where the SQL workload is captured and import it into another system a Reuse the SQL workload as an input source for other advisors such as the SQL Tuning Advisor and the SQL Access Advisor See Also a Oracle Database 2 Day Performance Tuning Guide for information about creating SQL tuning sets using Oracle Enterprise Manager a Oracle Database Performance Tuning Guide for information about creating SQL tuning sets using APIs Setting Up the Test System After you have captured the SQL workload into a SQL tuning set on the production system you can conduct SQL Performance Analyzer analysis on the same database where the workload was captured or on a different database Because the analysis is resource intensive it is recommended that you capture the workload on a production database and transport it to a separate test database where the analysis can be performed To do so export the SQL tuning set from the production system and import it into a separate system where the system change will be tested T
237. to External Systems page to verify the database links directory objects and Oracle Streams that may be referenced during the workload capture process There may be other references to external systems that are not included in these categories For more information see Resolving References to External Systems on page 11 2 Once all references to external systems have been verified and modified as necessary click Continue The Replay Workload Choose Initial Options page appears Replay Workload Initialize Options Database x112 Cancel Step 1 of 5 Next Capture Name CAPTURE x112 20100509051233 Logged In As IMMCHAN Replay Name REPLAY x112 20100510050326 SQL Performance Analyzer SQL Performance Analyzer allows you to test and to analyze the effects of changes on the execution performance of SQL contained in a SQL Tuning Set Capture SQL statements into a SQL Tuning Set during workload replay Identify Source Choose the initial replay options Use the default replay options Replay Name 8 Inthe Replay Name field you may enter a name for the replay or simply use the name generated by the system 9 Under SQL Performance Analyzer select whether to capture SQL statements into a SQL tuning set during workload replay Replaying a Database Workload 11 9 Replaying a Database Workload Using Enterprise Manager While Database Replay provide analysis of how a change affects your entire system you can use
238. ult value may cause additional overhead with some workloads and is not recommended Stopping a Workload Capture To stop the workload capture use the FINISH_CAPTURE procedure BEGIN DBMS_WORKLOAD_CAPTURE FINISH_CAPTURE END Capturing a Database Workload 9 15 Monitoring Workload Capture Using Views In this example the FINISH_CAPTURE procedure finalizes the workload capture and returns the database to a normal state Tip After capturing a workload on the production system you need to preprocess the captured workload as described in Chapter 10 Preprocessing a Database Workload Exporting AWR Data for Workload Capture Exporting AWR data enables detailed analysis of the workload This data is also required if you plan to run the Replay Compare Period report or the AWR Compare Period report on a pair of workload captures or replays To export AWR data use the EXPORT_AWR procedure BEGIN DBMS_WORKLOAD_CAPTURE EXPORT_AWR capture_id gt 2 END In this example the AWR snapshots that correspond to the workload capture with a capture ID of 2 are exported along with any SQL tuning set that may have been captured during workload capture The EXPORT_AWR procedure uses the capture_id required parameter which specifies the ID of the capture whose AWR snapshots will be exported This procedure will work only if the corresponding workload capture was performed in the current database
239. umber of concurrent users during replay The default value is 100 a The think_time_scale parameter scales the elapsed time between two successive user calls from the same session and is interpreted as a value Setting 11 20 Oracle Database Real Application Testing User s Guide Replaying a Database Workload Using APIs this parameter to 0 will send user calls to the database as fast as possible during replay The default value is 100 The think_time_auto_correct parameter corrects the think time based on the think_time_scale parameter between calls when user calls take longer to complete during replay than during capture This parameter can be set to either TRUE or FALSE Setting this parameter to TRUE reduces the think time if the workload replay is taking longer than the workload capture The default value is TRUE The scale_up_multiplier parameter defines the number of times the workload is scaled up during replay Each captured session will be replayed concurrently for as many times as specified by this parameter However only one session in each set of identical replay sessions will execute both queries and updates The rest of the sessions will only execute queries The capture_sts parameter specifies whether to capture a SQL tuning set in parallel with the workload replay If this parameter is set to TRUE you can capture a SQL tuning set during workload replay and use SQL Performance Analyzer to compare it to an
240. ve 7 Oracle Management Service DEFAULT Excluded Program OMS i Oracle Management Agent DEFAULT Excluded Program _ emagent Add Another Row 4 Select the workload capture options a Under Database Restart Options select whether the database will be restarted before workload capture It is recommended that the database be restarted before capturing a workload to enable a clean state for workload capture Otherwise potential problems may arise when replaying the workload For more information see Restarting the Database on page 9 2 a Under SQL Performance Analyzer select whether to capture SQL statements into a SQL tuning set during workload capture While Database Replay provide analysis of how a change affects your entire system you can use a SQL tuning set in conjunction with SQL Performance 9 6 Oracle Database Real Application Testing User s Guide Capturing a Database Workload Using Enterprise Manager Analyzer to gain a more SQL centric analysis of how the change affects SQL statements and execution plans By capturing a SQL tuning set during workload capture and another SQL tuning set during workload replay you can use SQL Performance Analyzer to compare these SQL tuning sets to each other without having to re execute the SQL statements This enables you to obtain a SQL Performance Analyzer report and compare the SQL performance before and after change
241. viewing Automatic Database Diagnostic Monitor ADDM reports to diagnose a new concurrency issue or running SQL Tuning Advisor to fix a new SQL performance problem The replay compare period report uses the following structure m General Information Analyzing Replayed Workload 12 9 Using Compare Period Reports This section contains metadata about the two runs being compared in the report Any init ora parameter changes between the two runs are also shown here a Replay Divergence This section contains the divergence analysis of the second run relative to the first Main Performance Statistics This section contains a high level performance statistic comparison across the two runs such as change in database time Top SQL by Change in DB Time This section compares the performance change of top SQL statements ordered by total changed in database time from one run to the next a Hardware Usage Comparison This section compares the hardware resource usage across the two runs a ADDM Comparison This section contains an ADDM report comparison across the two runs 12 10 Oracle Database Real Application Testing User s Guide Database Replay about 1 2 methodology 8 1 replay clients about 8 3 11 5 calibrating 11 5 starting 11 5 11 6 replay filter set about 11 4 reporting 8 3 12 1 compare period reports 12 6 12 7 usage 1 2 8 1 workflow 8 1 workload capture about 9 1 capture directory 9 3
242. while running Database Replay For information about comparing SQL tuning sets using SQL Performance Analyzer reports see Generating SOL Performance Analyzer Reports Using APIs on page 12 8 Note Capturing SQL statements into a SQL tuning set is the default and recommended workload capture option Under Workload Filters select whether to use exclusion filters by selecting Exclusion in the Filter Mode list or inclusion filters by selecting Inclusion in the Filter Mode list To add filters click Add Another Row and enter the filter name session attribute and value in the corresponding fields For more information see Using Filters with Workload Capture on page 9 3 After selecting the desired workload capture options click Next The Capture Workload Parameters page appears Capture Workload Parameters Database x090422 Cancel Back step 3 of 5 Next kK Step 3 of 5 Next Logged InAs IMMCHAN cD Gy a Workload Capture Parameters Capture Name CAPTURE x090422 20090501114705 Directory Object CAPTURE1 v Create Directory Object Select a directory object to hold the captured workload The selected directory must be empty Database Shutdown Parameters Immediate Rollback active transactions and disconnect all connected users O Transactional Disconnect all connected users after transactions have completed O Abort Instantaneous shutdown by aborting the database instance
243. y You must do this once for every captured workload Preprocessing is best performed in the test database The captured workload must be accessible from the test database 3 Replay Replay the 5 Workload preprocessed workload on a test copy of the production database aN au s View Workload Capture History Active Capture and Replay Directory Start SelectName Type Object Time No items found Capturing a Database Workload 9 5 Capturing a Database Workload Using Enterprise Manager 2 Inthe Go to Task column click the icon that corresponds to the Capture Workload task The Capture Workload Plan Environment page appears Capture Workload Plan Environment Database x090422 Cancel Ste f5 p 1 of 5 Next Logged In As IMMCHAN The following prerequisites should be met to avoni potential problems before proceeding to capture the workload Prerequisite JAcknowledge Make sure there is enough disk space to hold the captured workload Consider doing a short duration workload O capture and using it for estimating the disk space requirement of a full workload capture Make sure you can restore the replay database to match the capture database at the start of the workload capture Fl A successful workload replay depends on application transactions accessing application data identical to that on a capture system Common ways to restore application data state include point in time recovery flashback and
244. you want to use All replay clients must be able to resolve the net service name which can be done using a local tnsnames ora file a Usea separate connect descriptor or net service name for each client connect descriptor captured in the workload by selecting this option and for each capture system value entering a corresponding replay system value that will be used by the replay client For more information see Remapping Connections on page 11 3 12 Specify the replay options using the replay parameters To modify the replay behavior click the Replay Parameters tab and enter the desired values for each replay parameter Using the default values is recommended For information about setting the replay parameters see Specifying Replay Options on page 11 3 Connection Mappings Replay Parameters Some replay parameters can be modified to change the behavior of the replay Refer to the Oracle Real Application Testing User s Guide for more information Name Description Value synchronization This parameter determines what type of synchronization will be used during workload SCN v replay If this parameter is set to SCN the COMMIT order in the captured workload will be globally preserved during replay and all replayed requests will be executed only after all COMMIT actions with a lower capture time SCN have completed If this parameter is set to OBJECT_ID a finer method of synchronization is used which is based
245. ze the effects of optimizer statistics changes on SQL Tuning Set performance Exadata Simulation Simulate the effects of a Exadata Storage Server installation on SQL Tuning Set performance Guided Workflow Create a SQL Performance Analyzer Task and execute custom experiments using manually created SQL trials SQL Performance Analyzer Tasks Last Current Step SQLs Steps Select Name Owner Modified Name Type Status Processed Completed No SQL Performance Analyzer Tasks available E SVEE e 2 Under SQL Performance Analyzer Workflows select the workflow for creating the desired type of analysis task Upgrade from 9i or 10 1 Use the upgrade from 9i or 10 1 workflow to test a database upgrade from Oracle9i Database or Oracle Database 10g Release 1 to Oracle Database 10g Release 2 and newer releases as described in Upgrading from Oracle9i Database and Oracle Database 10g Release 1 on page 7 1 Upgrade from 10 2 or 11g Use the upgrade from 10 2 or 11g workflow to test a database upgrade from Oracle Database 10g Release 2 or Oracle Database 11 to a later release as described in Upgrading from Oracle Database 10g Release 2 and Newer Releases on page 7 10 a Parameter Change Use the parameter change workflow to determine how a database initialization parameter change will affect SQL performance as described in Using the Parameter Change Workflow on page 3 3 Optimizer Statistics Use t

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