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1. Notes 36 Data Manipulation Language DML 1 A PLAN clause may be used in all select expressions including subqueries derived tables and view definitions It can be also used in UPDATE and DELETE statements because they re im plicitly based on select expressions 2 Ifa PLAN clause contains some invalid retrieval description then either an error will be returned or this bad clause will be silently ignored depending on severity of the issue 3 ORDER lt navigational_index gt INDEX lt filter_indices gt kind of plan is reported by the engine and can be used in the user supplied plans starting with FB 2 0 Improvements in Sorting A Brinkman Some useful improvements have been made to SQL sorting operations Order By or Group By lt alias name gt Column aliases are now allowed in both these clauses Examples 1 ORDER BY ELECT RDBSRELATION_ID AS ID ROM RDBSRELATIONS RDER BY ID i tf 2 GROUP BY ELECT RDBSRELATION_NAME AS ID COUNT ROM RDBSRELATION_FIELDS ROUP BY ID Q no GROUP BY Arbitrary Expressions A GROUP BY condition can now be any valid expression Example GROUP BY SUBSTRING CAST A B 2 AS VARCHAR 15 FROM 1 FOR 2 37 Data Manipulation Language DML Order SELECT Sets by Degree Number Order by degree ordinal column position now works on a select list Example ECT ROM RDBSRELATION
2. IF NEW ID 3 THEN EXECUTE PROCEDURE ERR 1 IF NEW ID 4 THEN NEW ID 1 0 END CREATE OR ALTER PROCEDURE ERR 2 AS BEGIN INSERT INTO ERR VALUES 3 333 END 1 User exception from a trigger SQL INSERT INTO ERR VALUES 2 2 Statement failed SQLCODE 836 exception 3 ID 2 At trigger ERR_BI 2 User exception from a procedure called by a trigger SQL INSERT INTO ERR VALUES 3 3 Statement failed SQLCODE 836 exception 3 ID 3 At procedure ERR 1 At trigger ERR BI 3 Run time exception occurring in trigger division by zero SOL INSERT INTO ERR VALUES 4 4 Statement failed SQLCODE 802 arithmetic exception numeric overflow or string truncation At trigger ERR BI 52 Stored Procedure Language PSQL 4 User exception from procedure SQL EXECUTE PROCEDURE ERR_1 Statement failed SQLCODE 836 exception 3 ID 3 At procedure ERR 1 5 User exception from a procedure with a deeper call stack SOL EXECUTE PROCEDURE ERR 2 Statement failed SQLCODE 836 exception 3 ID 3 At procedure ERR_1 At trigger ERR BI At procedure ERR 2 Call a UDF as a Void Function Procedure N Samofatov In PSQL supported UDFs e g RDBSSET CONTEXT can be called as though they were void func tions a k a procedures in Object Pascal For example BEGIN RDBS SET CONTEXT
3. tabl reference table primary joined table table primary table derived derived table query expression lt left paren derived column list right paren gt derived column list Examples a Simple derived table AS table correlation name gt table reference lt column name gt lt comma gt table reference gt AS lt correlation name gt lt comma gt column name gt 23 Data Manipulation Language DML SELECI FROM SELECT RDBSRELATION NAME RDBSRELATION ID FROM RDBSRELATIONS AS R RELATION NAME RELATION ID b Aggregate on a derived table which also contains an aggregate SELECT DT FIELDS Count FROM SELECT RDBSRELATION NAME unt SRELATIONS R A T RDBSRELATION_FIELDS RF ON RF RDB RELATION_NAME R RDBSRELATION_NAM BY DBSRELATION_NAME AS DT RELATION_NAM O M D O U GR JJOGWOoQUWtE K UJ UU H UJ LH FIELDS GROUP B DT FTII Lr DS c UNION and ORDER BY example SELECT DT FROM SELECT RDBSRELATION NAM RDBSRELATION ID BJ BSRELATIONS R N ALL CT RDBSOWNER NAME RDBSRELATION ID HOUSE ER BY M DBSRELATIONS R AS DT WHERE
4. COMMIT 5 move data from temporary table and drop i INSERT INTO RDBS USERS RDBS USER NAME RDB SYS USER NAME RDBSGROUP NAME RDBSUID RDBSGID RDBSPRIVILEGE RDBSCOMMENT RDBSFIRST NAMI RDBS MIDDLE NAME RDB LAST NAME RDBSPASSWD SELECT USER NAME SYS USER NAME GROUP NAME UID GID PRIVILEGE COMMENT FIRST NAME MIDDLE NAME LAST NAME PASSWD FROM UTMP COMMIT Lr Cf zI Lr zI DROP TABLE UTMP COMMIT Note This field should be constrained as NOT NULL For information about this see Nullability of RDB PASSWD in the Security chapter 152
5. RDBSR RDBSDATABASE BSRELATION NAME R1 RDBSR LH ELATION NAM 41 Data Manipulation Language DML SELECT Statement amp Expression Syntax Dmitry Yemanov About the semantics A select statement is used to return data to the caller PSQL module or the client program Select expressions retrieve parts of data that construct columns that can be in either the final result set or in any of the intermediate sets Select expressions are also known as subqueries Syntax rules select statement select expression FOR UPDATE WITH LOCK select expression query specification UNION ALL DISTINCT query specification gt query specification ELECT FIRST lt value gt SKIP lt value gt select list ROM lt table expression list gt HERE lt search condition gt ROUP BY lt group value list gt AVING lt group condition gt LAN lt plan item list gt RDER BY lt sort value list gt ROWS lt value gt TO lt value gt OVGOQSa AN lt table expression gt lt table name gt lt joined table gt lt derived table gt joined table cross join qualified join lt cross join lt table expression gt CROSS JOIN lt table expression gt lt qualified join gt lt table expression gt INNER LEFT RIGHT FULL OUTER JOIN lt table expres ON join condition
6. Start your application Now start your application and it will use the embedded server as a both a client library and a server and will be able to access local datasases via the XNET network emulation protocol Installation Structure Examples c my_app app exe c my_app gds32 dll1l c my_app ib_util dll 114 INSTALLATION NOTES my_app icudt30 dll1 my_app icuin30 dl1l my_app icuuc30 dll my_app firebird conf my_app firebird msg my_app intl fbintl dll my_app intl fbintl conf my_app udf fbudf dll qgqaaaaaaa Suppose you want to place the Firebird files excluding the renamed fbembed dll in another direct ory In that case you need to modify your firebird conf and set RootDirectory to the Firebird directory tree that is parent to the Firebird files Example my_app app exe my_app gds32 d11l my_app ib_util dll my_app icudt30 d1l1 my_app icuin30 dll my_app icuuc30 dl1l1 my_app firebird conf fb firebird msg N bNintlNfbintl dl fb intl fbintl conf N bNudfN budf dll oo0o000000000Q In firebird conf RootDirectory d fb POSIX Platforms Originally by Mark O Donohue revised for 2 0 The Firebird server comes in two forms Classic which runs as a service and SuperServer which runs as a background daemon Classic is the more traditional UNIX service while Superserver uses threads rather than processes For the user just sta
7. 123 Bugs Fixed fixed by V Horsun Not registered Attaching with the isc_dpb_no_garbage_collect option was forcing a sweep fixed by V Horsun Not registered The system transaction was being reported as dead fixed by A dos Santos Fernandes V Horsun Not registered The server would lock up after an unsuccessful attach to the security database fixed by D Yemanov C Valderrama SF 1076858 Source of possible corruption in Classic server fixed by V Horsun SF 1116809 Incorrect data type conversion fixed by A dos Santos Fernandes SF 1111570 Problem dropping a table having a check constraint referencing more than one column fixed by C Valderrama Not registered Usage of an invalid index in an explicit plan caused garbage to be shown in the error message instead of the rejected index name fixed by C Valderrama SF 543106 Bug with ALL keyword MORE INFO REQUIRED fixed by D Yemanov Not registered System users AUTHENTICATOR and SWEEPER were lost causing SQL SERVER to be reported instead fixed by A Peshkov 124 Bugs Fixed Not registered Don t rollback prepared 2PC sub transaction Description needs clarifying Vlad fixed by V Horsun Not registered Memory consumption became exorbitant when blobs were converted from strings during request processing For example the problem would appear when running a script with a series of statements like insert into t a b values N lt literal_s
8. 2 isc info tra read committed isc info tra no rec version isc info tra rec version That is for Read Committed transactions two items are returned isolation level and record version ing policy while for other transactions one item is returned isolation level isc info tra access Returns the access mode read only or read write of the current transaction The format of the re turned clumplets is isc info tra access 1 isc info tra readonly isc info tra readwrite isc info tra lock timeout Returns the lock timeout set for the current transaction Improved Services API The following improvements have been added to the Services API Task Execution Optimized D Yemanov Services are now executed as threads rather than processes on some threadable CS builds currently 32 bit Windows and Solaris New Function for Delivering Error Text C Valderrama The new function fb interpret replaces the former isc_interprete for extracting the text for a Firebird error message from the error status vector to a client buffer 14 Changes to the Firebird API and ODS Important isc_interprete is vulnerable to overruns and is deprecated as unsafe The new function should be used instead ODS On Disk Structure Changes On disk structure ODS changes include the following New ODS Number Firebird 2 0 creates databases with an ODS On Disk Structure version of 11 Size limit for excepti
9. 40 Data Manipulation Language DML RDBSRELATION_NAME FROM RDBSRELATIONS R b The statement below will now correctly use the FieldID from the subquery and from the up dating table UPDATE TableA SET FieldA SELECT SUM A FieldB FROM TableA A WHERE A FieldID TableA FieldID Note In Firebird it is possible to provide an alias in an update statement but many other data base vendors do not support it These SQL statements will improve the interchangeabil ity of Firebird s SQL with other SQL database products c This example did not run correctly in Firebird 1 5 and earlier SELECT RDBSRELATIONS RDBSRELATION_NAME R2 RDBSRELATION NAME FROM RDBSRELATIONS JOIN RDBSRELATIONS R2 ON R2 RDBSRELATION NAME RDBSRELATIONS RDBSRELATION NAME If RDB RELATIONS contained 90 records it would return 90 90 8100 records but in Firebird 2 it will correctly return 90 records a This failed in Firebird 1 5 but is possible in Firebird 2 SELECT SELECT RDBSRELATION NAME FROM RDBSDATABASE FROM RDBSRELATIONS b Ambiguity checking in subqueries the query below would run in Firebird 1 5 without re porting an ambiguity but will report it in Firebird 2 ELECT SEL FI FROM RD ECT RST 1 RDI JOIN RDBSREL FROM R2 BSRELATIONS R1 ATIONS R2 ON ELATION NAME
10. Firebird 2 0 Release Notes Helen Borrie Collator Editor 1 November 2006 Document v 0200 101 for Firebird 2 0 Release Firebird 2 0 Release Notes 1 November 2006 Document v 0200_101 for Firebird 2 0 Release Helen Borrie Collator Editor Table of Contents ly General NOtes sneren isre on ariaa ae aaa i e aiaiai aasa o iriri a ariaa ees 1 lote a BF oI Ere E E E E E EE E E EN 1 Compatibility Issues neoini iinei ia iiion e ede pe eoe e tee Ee Mee eet pe edle He 1 Incomplete Implementations eesee Innen 1 Bug Reporting and Support 2 0 0 ce cccccececececececececececeeeeeeeeeeeeeeeeeseseeeeeeeees 2 Documentation emere eee oa Sees Dab SEE ek oaks eet eade aeie Leere tet neue ERE bee eas 3 The Prrebird Docs Project i e cete eee e ease teas 3 Your Main Documentation cccceeececececcceaeeneeeeeecececeaeaaeaeeneeceseceaaeaeeeeeeeeeeeeaea 3 2 Newin Firebird 2 0 ere cation n Eee Sada stg oe ritratto eee de heh etre ke dak steed bata exe rro des 4 Derived Tables ironinen neinei eee ee ere ee nde deuce tere ate enano ed dne 4 PSQL Now Supports Named Cursors sseeeee eene 4 Reimplemented Protocols on Windows eeeeeeee 4 Local Protocol XNET nee Rr Ree iet ee e aibre Eo tone esa soe eere Dee aa 4 Change to WNET NetBEUD Protocol seen nennen 5 Reworking of Garbage Collection 22 2 cecccececececececececeeeeeeeeeeeeeseseeeeeeeees 5 Porting of the
11. SQL Privileges Not registered Permissions were not being checked for view columns fixed by D Yemanov Not registered Privileges granted to procedures triggers views were being preserved after the ob ject had been dropped fixed by D Yemanov Not registered Column level SQL privileges were being preserved after the affected column was dropped fixed by D Yemanov SF 223128 SYSDBA could grant non existent roles fixed by D Yemanov 141 Bugs Fixed UDF Bugs Not registered There were thread safety issues in datetime functions of the FBUDF library fixed by C Valderrama Not registered The UDF AddMonth in the UDF library FBUDF had a bug that displayed itself when the calculation rolled the month past the end of the year fixed by C Valderrama Not registered Diagnostics when a UDF module was missing unusable needed improvement fixed by A Peshkov Not registered There were some problems with the mapping of UDF arguments to parameters fixed by N Samofatov Not registered UDF arguments were being prepared optimized twice fixed by D Yemanov SF 544132 728839 Nulls handling in UDFs was causing problems fixed by C Valderrama Not registered UDF access checking was incorrect fixed by D Yemanov gbak Not registered There were issues with restoring if indexes used in explicit plans inside PSQL code had been dropped fixed by A dos Santos Fernandes 142 Bugs Fixed Not regis
12. 2 0 SuperServer starts up Classic Server on POSIX For reasons both technical and historical a Classic server on POSIX with embedded clients is espe cially vulnerable to security exposure Users having embedded access to databases MUST be given at least read access to the security database This is the main reason that made implementing enhanced password hashes an absolute requirement A malicious user with user level access to Firebird could easily steal a copy of the security database 76 Security in Firebird 2 take it home and quietly brute force the old DES hashes Afterwards he could change data in critical databases stored on that server Firebird 2 is much less vulnerable to this kind of compromise But the embedded POSIX server had one more problem with security its implementation of the Ser vices API calls the command line gsec as normal users do Therefore an embedded user maintenance utility must have full access to security database The main reason to restrict direct access to the security database was to protect it from access by old versions of client software Fortuitously it also minimizes the exposure of the embedded Classic on POSIX at the same time since it is quite unlikely that the combination of an old client and the new server would be present on the production box Caution However the level of Firebird security is still not satisfactory in one serious respect so please read this section ca
13. DT RDBSRELATION_ID lt 4 Points to Note Every column in the derived table must have a name Unnamed expressions like constants should be added with an alias or the column list should be used The number of columns in the column list should be the same as the number of columns from the query expression The optimizer can handle a derived table very efficiently However if the derived table is involved in an inner join and contains a subquery then no join order can be made 24 Ly Data Manipulation Language DML ROLLBACK RETAIN Syntax D Yemanov The ROLLBACK RETAIN statement is now supported in DSQL A rollback retaining feature was introduced in InterBase 6 0 but this rollback mode could be used only via an API call to isc_rollback_retaining By contrast commit retaining could be used either via an API call to isc_commit_retaining or by using a DSQL COMMIT RETAIN statement Firebird 2 0 adds an optional RETAIN clause to the DSQL ROLLBACK statement to make it consistent with COMMIT RETAIN Syntax pattern follows that of COMMIT RETAIN ROWS Syntax D Yemanov ROWS syntax is used to limit the number of rows retrieved from a select expression For an upper most level select statement it would specify the number of rows to be returned to the host program A more understandable alternative to the FIRST SKIP clauses the ROWS syntax accords with the latest SQL standard
14. There is no command line option to toggle headings off Using SET will display the state of SET HEAD along with other switches that can be toggled on off in the isql shell SHOW SYSTEM now shows predefined UDFs The SHOW object type command is meant to show user objects of that type The SHOW SYS TEM commmand is meant to show system objects but until now it only showed system tables Now it lists the predefined system UDFs incorporated into FB 2 84 Command line Utilities It may be enhanced to list system views if we create some of them in the future SET SQLDA_DISPLAY ON OFF A dos Santos Fernandes This SQLDA_DISPLAY command shows the input SQLDA parameters of INSERTs UPDATEs and DELETEs It was previously available only in DEBUG builds and has now been promoted to the pub lic builds It shows the information for raw SQLVARs Each SQLVAR represents a field in the XSQLDA the main structure used in the FB API to talk to clients transferring data into and out of the server Note The state of this option is not included in the output when you type SET in isql to see the cur rent settings of most options SET TRANSACTION Enhanced C Valderrama The SET TRANSACTION statement has been enhanced so that now all TPB options are supported NO AUTO UNDO IGNORE LIMBO LOCK TIMEOUT number Example SET TRANSACTION WAIT SNAPSHOT NO AUTO UNDO LOCK TIMEOUT 10 See also the document
15. checked on There is also a drop down for a custom installation which new users can safely ignore The next screen of interest enables you to set up how you want the server to run E Setup Firebird Database Server 2 0 Select Additional Tasks B Which additional tasks should be performed Q Select the additional tasks you would like Setup to perform while installing Firebird Database Server 2 0 then click Next V Use the Guardian to control the server Run Firebird server as C Run as an Application Run as a Service v Start Firebird automatically everytime you boot up v Install Control Panel Applet Copy Firebird client library to system directory v Generate client library as GDS32 DLL for legacy app support lt Back Cancel English Choose the options you want according to your choice of server model Use the Guardian Guardian is a utility than can run over the top of Superserver and restart it if it crashes for any reason If you chose the Classic server the Guardian option won t appear For deployment of Superserver on Win9x WinME and WinNT 4 0 using Guardian can avoid the situation where the server stops serving and nobody can find the DBA to restart it On other Win32 platforms you can set the operating system to restart the service instead and not bother with the Guardian Service or application If you select to install Superserver or Classic and your O
16. older isc4 gdb security databases before you uninstall the older Firebird server and set out to install Firebird 2 0 Before you proceed restore these backups in a temporary location using the old gbak and verify that the backups are good Compatibility Issues Naturally with so much bug removal and closing of holes there are sure to be things that worked be fore and now no longer work A collection of Known Compatibility Issues is provided to assist you to work out what needs to be done in your existing system to make it compatible with Firebird 2 0 Give special attention to the changes required in the area of user authentication Incomplete Implementations In a couple of areas planned implementations could not be completed for the v 2 0 release and will be deferred to later sub releases 64 bit Support General Notes 64 bit builds for both Superserver and Classic are ready and available for installing on Linux Note that the 64 bit ports have been done and tested for AMD64 only These builds should also work on Intel EM64T The Intel IA 64 platform is not supported in this release A FreeBSD port of the 64 bit builds has also been done Win64 hosts are running without problems and the MS VCS final release seems to work satisfact orily so we are able to say we are no longer hampered by problems with the Microsoft compiler The Win64 port is complete and into testing but is still considered experimental It will become
17. that is in the upgrade sub directory of your Firebird server installation Note A copy of the script appears in the Appendix to these notes Security Upgrade Script Doing the Security Database Upgrade To do the upgrade follow these steps 1 Put your old security database in some place known to you but not in Firebird s new home dir TI Security in Firebird 2 ectory Keep a copy available at all times 2 Start Firebird 2 using its new native security2 fdb 3 Convert your old security database to ODS11 i e backup and restore it using Firebird 2 0 Without this step running the security database sql script will fail 4 Connect the restored security database as SYSDBA and run the script 5 Stop the Firebird service 6 Copy the upgraded database to the Firebird 2 home directory as security2 fdb 7 Restart Firebird Now you should be able to connect to the Firebird 2 server using your old logins and passwords Nullability of RDB PASSWD In pre 2 0 versions of Firebird it was possible to have a user with NULL password From v 2 0 on ward the RDBSPASSWD field in the security database is constrained as NOT NULL However to avoid exceptions during the upgrade process the field is created as nullable by the up grade script If you are really sure you have no empty passwords in the security database you may modify the script yourself For example you may edit the line RDBSPASSWD RDBSPA
18. usr bin for the init d script and an etc rc config Firebird entry is created 8 Starts the server service Firebird should start automatically in runlevel 2 3 or 5 9 Generates and sets a new random SYSDBA password and stores it in the file opt firebird S YSDBA password 10 Adds an entry to aliases conf for the sample database employee fdb Testing your Linux installation Step 1 Accessing a database In a shell cd opt firebird bin S isql user sysdba password password SQL gt connect localhost employee fdb this is an aliased path SQL gt select from sales SQL gt select rdbSrelation_name from rdb relations SQL gt help SQL gt quit Note 1A password has been generated for you on installation It can be obtained from the opt firebird SYSDBA password file located in the Firebird root directory Step 2 Creating a database The Firebird server runs by default as the user firebird While this has always been the recommended configuration the previous default was for the server to run as root user When running as root user the server had quite wide ranging ability to read create and delete database files anywhere on the POSIX filesystem For security reasons the service should have a more limited ability to read delete and create files While the new configuration is better from a security perspective it requires some special considera tions to be taken int
19. 20 Usage Enh ncemnients 55 nece rene eee esee e Fre eee oae dudes 20 5 Data Manipulation Language DML sess emen ememenenen 22 New and Extended DSQL Syntaxes sssseeee Inneren 22 EXECUTE BLOCK Statement nenene eiee tenente nere leen A EEs 22 Derived Tables eire Eee 23 ROLLBACK RETAIN Syntax seie ai esee nete eene ae ea a 25 ROWSsS yiltax eaa e ea eA iE EAE AE gelten V eR PEE EAEn 25 Enhancements to UNION Handling 000 0 cccececececececececeeeeeeeeeeeeeeeeeees 26 TIF Expression Syntax Added erinnere eesriie iai ii 27 CASTO Behaviour Improved 20 2 cceeecececcceaeeneeeeeececececeaaeaeeeeeeeeeeceaaaaeeeeeeeeeeeeaea 27 Built in Function SUBSTRING Enhanced esee 28 Enhancements to NULL Lo ste e orienter eee trece tinere n eene p ee Rose eh 28 CROSS JOIN is Now Supported ccnt einion eene 30 Subqueries and INSERT Statements Can Now Accept UNION Sets 31 New Extensions to UPDATE and DELETE Syntaxes eR 31 New Context Variables 5 ere espe eter bere festa rte edite pea ge i BRE nte eg 31 Improvements in Handling User specified Query Plans sesessses 35 Improvements in Sorting III e emere nnne nn ne 37 NEXT VALUE FOR Expression Syntax sseeee Ie 38 RETURNING Clause for Insert Statements see 39 DSQL parsing of table aliases is Stricter se rerereseseresessse 40 SEL
20. 839 Windows Instclient exe failed to install gds32 dll over an existing version from V1 5 1 or later fixed by P Reeves 145 Bugs Fixed 146 Chapter 18 Firebird 2 0 Project Teams Table 18 1 Firebird Development Teams Developer Country Major Tasks Dmitry Yemanov Russian Full time database engineer implementor core team Federation leader Alex Peshkoff Russian Security features coordinator and author code fixer Federation Linux buildmaster Claudio Valderrama Chile Code scrutineer bug finder and fixer ISQL enhance ments UDF fixer designer and implementor Vladislav Horsun Ukraine DB engineer SQL feature designer implementor Arno Brinkman The Nether Indexing and Optimizer enhancements new DSQL fea lands tures Adriano dos Santos Brazil New international character set handling text and text Fernandes BLOB enhancements new DSQL features code scru tineering Nickolay Samofatov Russian Designed and implemented new inline NBackup code Federation fixer DB engineer Canada Paul Beach France Release Manager HP UX builds Pavel Cisar Czech Re QA tools designer coordinator public Philippe Makowski France QA tester Paul Reeves France Win32 installers and builds Sean Leyne Canada Bugtracker organizer Dimitrios Ioannides Greece New Jira bugtracker implementor 147 Firebird 2 0 Project Teams
21. C Valderrama V Horsun gpre SF 504978 gpre variable names were being truncated fixed by C Valderrama SF 527677 gpre ANSI85 compatible COBOL switch was broken fixed by C Valderrama SF 1103666 gpre was using inconsistent lengths fixed by C Valderrama SF 1103670 gpre would invalidate a quoted cursor name after it was opened fixed by C Valderrama SF 1103683 gpre was not checking the length of the DB alias fixed by C Valderrama SF 1103740 gpre did not detect duplicate quoted cursor names fixed by C Valderrama Not registered gpre could not generate more than 32 000 identifiers fixed by A Harrison gstat Not registered Error output by gstat on Windows 32 was incorrect fixed by C Valderrama 144 Bugs Fixed fb_lock_print Not registered fb_lock_print could fail with an exception message the requested operation can not be performed on a file with a user mapped section open fixed by V Horsun Linux Installs SF 1011401 The start stop script was breaking halt reboot on Slackware by A Peshkov Code Clean up Not a bug L ocal command line switch for SS on Win32 is gone by D Yemanov Assorted clean up Extensive ongoing code cleanup and style standardization Broken write ahead logging WAL and journalling code is fully cleaned out by C Valderrama Platform specific Not registered SuSE Linux Service would not restart correctly on SuSE Linux by A Peshkov CORE
22. CREATE DOMAIN RDBS USER NAME AS VARCHAR 128 CHARACTER SET UNICODE_FSS CREATE DOMAIN RDBSUSER_PRIVILEGE AS INTEGER COMMIT CREATE TABLE RDBSUSERS RDBS USER NAME RDBSUSER NAME NOT NULL PRIMARY KEY local system user nam for setuid for file permissions RDBS SYS USER NAME RDBSUSER NAME RDBSGROUP NAME RDBSUSER NAME RDBSUID RDBSUID RDBSGID RDBSGID RDBSPASSWD RDBSPASSWD SEE NOTE BELOW Privilege level of user mark a user as having DBA privilege RDBSPRIVILEGE RDBSUSER_PRIVILEGE RDBSCOMMENT RDBSCOMMENT RDBSFIRST_NAME RDBSNAME PART RDBSMIDDLE_NAME RDBSNAME PART RDBSLAST_NAME RDBSNAME PART COMMIT CREATE VIEW USERS USER NAME SYS USER NAME GROUP NAME UID GID PASSWD PRIVILEGE COMMENT FIRST NAME MIDDLE NAME LAST NAME FULL NAME AS SELECT RDBSUSER NAME RDB SYS USER NAME RDB GROUP NAME RDBSUID RDBSGID RDBSPASSWD RDBSPRIVILEGE RDBSCOMMENT RDBSFIRST_NAME RDBSMIDDLE_NAME RDBSLAST_NAME RDBSfirst_name _UNICODE_FSS RDBSmiddle_name 151 Appendix to Firebird 2 Release Notes _UNICODE_FSS RDB last name FROM RDBSUSERS WHERE CURRENT USER SYSDBA OR CURRENT USER RDBSUSERS RDBSUSER NAME COMMIT GRANT ALL ON RDBSUSERS to VIEW USERS R GRANT SELECT ON USERS to PUBLIC GRANT UPDATE PASSWD GROUP NAME UID GID FIRST NAME MIDDLE NAME LAST NAME ON USERS TO PUBLIC D
23. Command line Utilities These are prohibited gfix shut single force 0 gfix shut multi force 0 gfix online gfix online full gfix shut force 0 gfix online single 89 Chapter 13 External Functions UDFs Ability to Signal SQL NULL via a Null Pointer C Valderrama Previous to Firebird 2 UDF authors only could guess that their UDFs might return a null but they had no way to ascertain it This led to several problems with UDFs It would often be assumed that a null string would be passed as an empty string a null numeric would be equivalent to zero and a null date would mean the base date used by the engine For a numeric value the author could not always assume null if the UDF was compiled for an envir onment where it was known that null was not normally recognized Several UDFs including the ib_udf library distributed with Firebird assumed that an empty string was more likely to signal a null parameter than a string of length zero The trick may work with CHAR type since the minimum declared CHAR length is one and would contain a blank character normally hence binary zero in the first position would have the effect of signalling NULL However but it is not applicable to VARCHAR or CSTRING where a length of zero is valid The other solution was to rely on raw descriptors but this imposes a lot more things to check than they would want to tackle The biggest problem is that the engine wo
24. Start Guides for Firebird versions 1 5 and 2 0 in English and several other languages For the official documentation we use a Docbook XML format for sources and build PDF and HTML output using a suite of Java utilities customised for our purposes These notes were developed and built under this system Paul Vinkenoog has written comprehensive easy to follow manuals for writing Firebird documenta tion and for using our tools You can find links to these manuals in the aforementioned index New team members who want to do some writing or translating are always more than welcome We have a lab forum for documenters and translators firebird docs which you can join by visiting the Lists and Newsgroups page at the Firebird web site Your Main Documentation These release notes are your main documentation for Firebird 2 However if you are unfamiliar with previous Firebird versions you will also need the release notes for Firebird 1 5 3 For convenience copies of both sets of release notes are included in the binary kits They will be installed in the doc directory beneath the Firebird root directory Several other useful README documents are also in stalled there For future reference if you ever need to get a copy of the latest release notes before beginning install ation you can download them from the Firebird web site The link can be found on the same page that linked you to the binary kits towards the bottom of the page If you do n
25. Streams Distribute UNION conjunctions to the inner streams when possible Improved Handling of CROSS JOIN and Merge SORT Improved cross join and merge sort handling 62 Optimizations Better Choice of Join Order for Mixed Inner Outer Joins Let s choose a reasonable join order for intermixed inner and outer joins Equality Comparison on Expressions MERGE PLAN may now be generated for joins using equality comparsion on expressions For ODS 11 Databases only This group of optimizations affects databases that were created under Firebird 2 Segment level Selectivities are Used See Selectivity Maintenance per Segment in the Indexing chapter Better Support for IS NULL and STARTING WITH Previously IS NULL and STARTING WITH predicates were optimized separately from others thus causing non optimal plans in complex ANDed ORed boolean expressions From v2 0 and ODS11 these predicates are optimized in a regular way and hence benefit from all possible optimization strategies Matching of Both OR and AND Nodes to Indexes Complex boolean expressions consisting of many AND OR predicates are now entirely mapped to available indices if at all possible Previously such complex expressions could be optimized badly Better JOIN Orders Cost estimations have been improved in order to improve JOIN orders Indexed Order Enabled for Outer Joins It is now possible for indexed order to be utilised for outer joins i e navigationa
26. USER TRANSACTION MY VAR 123 END 53 Chapter 8 Enhancements to Indexing 252 byte index length limit is gone A Brinkman New and reworked index code is very fast and tolerant of large numbers of duplicates The old ag gregate key length limit of 252 bytes is removed Now the limit depends on page size the maximum size of the key in bytes is 1 4 of the page size 512 on 2048 1024 on 4096 etc A 40 bit record number is included on non leaf level pages and duplicates key entries are sorted by this number Expression Indexes O Loa D Yemanov A Karyakin Arbitrary expressions applied to values in a row in dynamic DDL can now be indexed allowing in dexed access paths to be available for search predicates that are based on expressions Syntax Pattern CREATE UNIQUE ASC ENDING DESC ENDING INDEX index name ON table name COMPUTED BY value expression Examples 1 CREATE INDEX IDX1 ON T1 COMPUTED BY UPPER COL1 COLLATE PXW_CYRL COMMIT LESI SELECT FROM T1 T WHERE UPPER COL1 COLLATE PXW CYRL OOAA PLAN T1 INDEX IDX1 CREATE INDEX IDX2 ON T2 COMPUTED BY EXTRACT YEAR FROM COL2 EXTRACT MONTH FROM COL2 COMMIT JURE SELECT FROM T2 ORDER BY EXTRACT YEAR FROM COL2 EXTRACT MONTH FROM COL2 PLAN T2 ORDER IDX2 54 Enhancements to Indexing Note 1 The e
27. alter table test alter fld type numeric 18 3 select fld 3 from test returns 0 033 instead of expected 0 333 fixed by D Yemanov SF 1184099 Incorrect padding was exhibited when using character set OCTETS fixed by C Valderrama A dos Santos Fernandes Not registered Unexpected errors were occurring because of improperly handled dead record versions created by the system transaction during DDL operations 128 Bugs Fixed fixed by A Harrison SF 223060 Processing of the GREATER THAN operator was too slow fixed by V Horsun Not registered CHECK constraints were not SQL compliant with regard to the handling of NULL Until now if NULL were to be allowed it had to be specified explicitly in the constraint definition Under the standard NULL is allowed unless explicitly constrained by NOT NULL or CHECK IS NOT NULL Example of Problem The following definition now allows NULL in DEPTNO where previously it did not CHECK DEPTNO IN 10 20 30 fixed by P Ruizendaal D Yemanov Not registered It was possible to create a primary key constraint on a column consisting of NULLs Example of Problem create table bug f1 int not null f2 int not null insert into bug f1 f2 values 1 1 commit alter table bug add pk int not null primary key fixed by V Horsun SF 1334034 REVOKE was damaging the ACL Access Control List fixed by D Yemanov 129 Bugs Fixed Services M
28. client passed more than the supported number of remote protocol versions fixed by A Karyakin A Peshkov Not registered An AV could occur when the server was configured to use TCP packets as large as 32 Kb fixed by C Valderrama A Peshkov Not registered Server would crash if a positioned UPDATE DELETE executed via DSQL was referencing a cursor that had already been released fixed by V Horsun Not registered Certain DDL actions could crash the server Example of a problem action alter table rdbSrelations add rdbSgarbage varchar 30 fixed by J Starkey Not registered An overflow in the plan buffer would cause the server to crash fixed by D Yemanov Not registered Possible server lockup crash when RELEASE SAVEPOINT xxx ONLY syntax is used or when existing savepoint name is reused in transaction context fixed by N Samofatov Not registered Rare client crashes caused by improperly cleaned XDR packets fixed by D Yemanov Not registered Server crash during SuperServer shutdown 134 Bugs Fixed fixed by A Peshkov SF 1057538 The server would crash if the output parameter of a UDF was not the last paramet er fixed by C Valderrama Not registered A number of possible server crash conditions had been reported by Valgrind fixed by N Samofatov Not registered Server would crash when a wrong type or domain name was specified when chan ging the data type for a column fixed by N Samofatov Not r
29. could cause index data corruption fixed by V Horsun SF 1446987 BLOBs could appear to be damaged during operations in PSQL causing a BLOB not found error fixed by V Horsun SF 1434147 Bugs with COUNT DISTINCT XXXX when XXXX was a high integer fixed by V Horsun 122 Bugs Fixed SF 1435997 A bug was causing a close database error 901 on the embedded server fixed by D Yemanov SF 1436066 Adding an index during database activity could cause logical errors in structure that GFIX would detect fixed by V Horsun Not registered A few types of subqueries were being wrongly treated as variant causing per formance issues fixed by D Yemanov Not registered Previously the Transaction ID would silently and dangerously overflow Now it will throw a consistency check when it reaches the limit which is still 2431 fixed by V Horsun Not registered Read committed transactions would block garbage collection unnecessarily fixed by V Horsun Not registered The ALL predicate could return wrong results fixed by D Yemanov SF 1404157 DFW was not ready for RECREATE TABLE VIEW fixed by D Yemanov Not registered Restored the code which replaces ROLLBACK with COMMIT if a transaction has not modified any data fixed by D Yemanov Not registered There were some bugs producing wrong statistics e with relation index data longer than 2432 bytes when the average index key length rounded to an integer value
30. dere ESTHER e PE RERD Ce eras eon er E wees 11 3 Changes to the Firebird API and ODS 1 eene 12 API Application Programming Interface sseee 12 Cleanu p ofabased 43 cda deed eee 12 Lock Timeout for WAIT Transactions 12 isc dsql sql info Now Includes Relation Aliases seeeeeeeeeees 12 Enhancement to isc blob lookup desc seeseeeeee 12 API Identifies Client Version eeeeee Ie eene 13 Additions to the isc database info Structure ssssssssseeeee 13 Additions to the isc transaction info Structure sssesseeeee 13 Improved Services APE n ee ete Ee eceet ee eee pene etie e SEERE SEE 14 ODS On Disk Structure Changes esses nnne 15 4 Data Definition Language DDL eese hen 17 New and Enhanced Syntaxes aini eneenen eene hhn nennen nnne 17 CREATE SEQUENCE 1 3 4 eere en Heredes 17 REVOKE ADMIN OPTION FROM eeenIIIIIIImeIeme emere nnne 18 Firebird 2 0 Release Notes SET DROP DEFAULT Clauses for ALTER TABLE ee 18 New Syntaxes for Changing Exceptions ssseeeIIeeeer 18 ALTER EXTERNAL FUNCTION 3 etie ette eerte nat 19 COMMENT Statement Implemented eseeeeeeee 19 Extensions to CREATE VIEW Specification seeeeIIII 20 RECREATE TRIGGER Statement Implemented eeeeeeeee
31. eee ee eeecececececeeececeeeceeeseceeeeeeeeeeeees 55 Firebird Index Structure from ODS11 Onward o0 eee cececececereceteteteees 56 New flag for the new index structure sssseee eee 57 Duplicate modes c tte ee erroe setote e net conte eiei hee iei e tote s ene poer aieea 57 JUMP NODES ier Ree ee ie eed eet Ree 58 NUED State e ne ete et tet iren e tional io e prre Er ne eee Eee TE 59 EX Un ERE 61 Improved PLAN Clause Hee hee 61 Optimizer Improvements 0 0 0 0 cece eeeeeeeecececececececececececececececececeeeseceeeeeeeeeeeeeees 61 Firebird 2 0 Release Notes For All Databases censere ecien iii iae ijiner eee ger epe nete e geste tbe eaten tie eg ed 61 For ODS 1I Databases only iere penetret ener et Ree EH Re Penne sect edes 63 10 New Featur s for Text Data iuit Rt ertet eng 64 New String Punctions oat tee pe eet Lote ele peneeate eger tes pet edet teg dee tegat aea dtt aperta 64 LOWEBR uenenum RETE ots 64 TRIMO 5 e entree teret n teet eelet ER Eb Me teceays 64 New String Size FUNCIONS sc 12 reete ette rense eie eene cela ete Pech dere Dre e PEE BASES 65 New INTL Interface for Non ASCII Character Sets sseeeee 66 Architecture oastei see ade eee e estet ette eet ee eee e Rea Esa oaia ia eiaa 66 Enhancements enee E EAEE ERO tegebat tere k e e Pe pale e epe e IEEE NES 66 New Character Sets and Collations Implemented eeeeee 70 Ch racter Set BU
32. eee teet ires 105 READ THIS FIRST reete er ere pre e ree Ee a 105 Other Pre installation Issues sse emen emen eene 107 Using the Win32 Firebird Installer eee 109 Installing Superserver from a zip Kit 22 2 cece cece cece ce cecececececeeeeeeeeeseeeeeeeeeees 111 Other Win32ISsues 2 2 i PER AEA a een Be leds 112 Updated Notes for Windows Embedded seeeeeee 113 POSIX Platforms lt j 2 bereitet eee eee ote re ege e edet bee cake Pb aee gend 115 READ THIS EIRST 224r enero rene ert eee ceo bre tese Yee clap rete tre eeu EVERA 115 Installing on Linux niinno i riiin ette edd ee te eset ee eed te e etat pee ded 117 Testing your Linux installation eeee ee eene 118 Utility Scripts i eee eere ederet terere e 120 Linux Seryer Tips pet e EE Suet cents be bee oh Meenas Dobe ie pe toco Er sete 120 Uninstalling on Linux ie ee CE RR easiness 121 Sol eT o E D E 121 BUENOS CREE 121 FreeBSD erae esce reete ne Deoa te erede neca eo pe ed ine De exte ee esa e etate pepe dese 121 Debian 1c EIE Geb GR bebe E GP epe eate ego ebrio leesesitvencentetaoess 121 DL Bus Fixed 5 cheer ee Ite premeret eee pe esee av Deuce Eye er Y ence ve ene ee LY Deae e pande 122 General Engine BUgs e eerie ete Lese et eo eset eee diee erede se edet 122 Services Manager 2 d eee eese Re eie e EE ERIM 130 GPIX BUGS pe P 130 PSOL Bugs IM 130 PSOE Bugs E E a
33. effect is to slow down InterBase Firebird database access to a virtual standstill as the files are backed up every time an I O operation occurs On XP there is no System Restore on the NET Servers A file in the Windows directory of ME c windows system filelist xml contains protected file types gdb is named there Charlie Caro originally recommended deleting the GDB extension from the includes section of this file However since then it has been demonstrated that Win ME might be rebuilding this list In XP it is not possible to edit filelist xml at all On ME the permanent workarounds suggested are one of use FDB Firebird DB as the extension for your primary database files RECOMMENDED move databases to C My Documents which is ignored by System Restore switch off System Restore entirely consult Windows doc for instructions On Windows XP Home and Professional editions you can move your databases to a separate parti tion and set System Restore to exclude that volume Windows XP uses smart copy so the overhead seen in Windows ME may be less of an issue on XP for smaller files at least For larger files e g Firebird database files natch there doesn t seem to be a better answer as long as you have gdb files located in the general filesystem Updated Notes for Windows Embedded Some changes between Firebird 1 5 and Firebird 2 0 mean the existing docs are slightly out of date For convenience the fol
34. from the port At this point ports were being scanned for incoming packets only by calculating timeout interval since last packet received for each port in the loop If the next packet from a particular port did not come for example because of an unplugged jack the only way to interrupt this receive and allow the main server loop to carry on processing the other ports was to wait for the keepalive TCP timeout to elapse on the abandoned connection Given that the default keepalive value is two hours it would ap pear that the Superserver was hung fixed by A Peshkov SF 1260310 Nessus vulnerability scanning could cause the server to drop connections fixed by A Peshkov SF 1065511 Clients on Windows XP SP2 were slow connecting to a Linux server fixed by N Samofatov SF 1065511 Clients on Windows XP SP2 were slow connecting to a Linux server fixed by N Samofatov SF 571026 INET INET_connect gethostbyname was not working properly fixed by D Yemanov SF 223058 Multi hop server capability was broken 137 Bugs Fixed fixed by D Yemanov Not registered Fixed memory leak from connection pool in isc_database_info fixed by N Samofatov Not registered Database aliases were not working in WNET fixed by D Yemanov Not registered Client would crash while disconnecting with an active event listener fixed by D Yemanov Not registered The client library would not react to environment variables being set via SetE
35. generates the pseudo random value srand unsigned time NULL return float rand float RAND MAX The problem with this algorithm is that it will return the same value for two calls done within a second To work around this issue rand was changed in Firebird 2 0 so that the starting point is not set expli citly This ensures that different values will always be returned 91 External Functions UDFs In order to keep the legacy behaviour available in case somebody needs it srand has been intro duced It does exactly the same as the old rand did IB UDF lower The function IB UDF 1ower in the IB UDF library might conflict with the new internal function lower if you try to declare it in a database using the ib_udf sql script from a previous Firebird version ib udf sql declaration that now causes conflict DECLARE EXTERNAL FUNCTION lower CSTRING 255 RETURNS CSTRING 255 FREE IT ENTRY POINT IB UDF lower MODULE NAME ib udf The problem will be resolved in the latest version of the new ib_udf2 sql script where the old UDF is declared using a quoted identifier New declaration in ib udf2 sql DECLARE EXTERNAL FUNCTION LOWER CSTRING 255 NULL RETURNS CSTRING 255 FREE IT ENTRY POINT IB UDF lower MODULE NAME ib udf Gi Tip It is preferable to use the internal function LOWERY
36. he does note even need login access to the external server Such a gateway easily overrides a firewall that is protecting your LAN from outside attack Details of the Security Changes in Firebird 2 0 Security focus was directed at some recognised weaknesses in Firebird s security from malicious at tacks the lack of brute force resistant passwords encryption in the security database the ability for any remote user with a valid account to open the security database and read hashes from it especially interesting in combination with the first point the inability for users to change their own passwords the lack of protection against remote brute forcing of passwords on the server directly 74 Security in Firebird 2 Authentication Firebird authentication checks a server wide security database in order to decide whether a database or server connection request is authorised The security database stores the user names and passwords of all authorised login identities Firebird 1 5 Authentication In Firebird 1 5 the DES algorithm is used twice to hash the password first by the client then by the server before comparing it with the hash stored in security database However this sequence becomes completely broken when the SYSDBA changes a password The client performs the hash calculation twice and stores the resulting hash directly in the security database Therefore hash management is completely client depend
37. in the SQL specification whereas GENERATOR is a legacy In terBase syntax term Use of the standard SEQUENCE syntax in your applications is recommended A sequence generator is a mechanism for generating successive exact numeric values one at a time A sequence generator is a named schema object In dialect 3 it is a BIGINT in dialect 1 it is an IN TEGER Syntax patterns CREATE SEQUENCE GENERATOR lt name gt DROP SEQUENCE GENERATOR name SET GENERATOR name TO start value ALTER SEQUENCE name RESTART WITH start value GEN ID name increment value NEXT VALUE FOR name Examples l CREATE SEQUENCE EMPLOYEE ALTER SEQUENCE S EMPLOYEE RESTART WITH 0 See also the notes about NEXT VALUE FOR 17 Data Definition Language DDL Warning ALTER SEQUENCE like SET GENERATOR is a good way to screw up the generation of key values REVOKE ADMIN OPTION FROM D Yemanov SYSDBA the database creator or the owner of an object can grant rights on that object to other users However those rights can be made inheritable too By using WITH GRANT OPTION the grantor gives the grantee the right to become a grantor of the same rights in turn This ability can be removed by the original grantor with REVOKE GRANT OPTION FROM user However there s a second form that involves roles Instead of specifying the same rights for many users soon
38. make remote connection to the security database completely im possible Don t be surprised if some old program fails on attempting direct access this is by design Users information may now be accessed only through the Services API and the equivalent internal ac cess to services now implemented in the isc user API functions Protection from Brute force Hacking Current high speed CPUs and fast WAN connections make it possible to try to brute force Firebird server users passwords This is especially dangerous for Superserver which since Firebird 1 5 per forms user authentication very fast Classic is slower since it has to create new process for each con nection attach to the security database within that connection and compile a request to the table RDBSUSERS before validating login and password Superserver caches the connection and request thus enabling a much faster user validation Given the 8 byte maximum length of the traditional Firebird password the brute force hacker had a reasonable chance to break into the Firebird installation The v 2 0 Superserver has active protection to make a brute force attack more difficult After a few failed attempts to log in the user and IP address are locked for a few seconds denying any attempt to log in with that particular user name OR from that particular IP address for a brief period No setup or configuration is required for this feature It is active automatically as soon as the Firebird
39. multi byte BLOBs was being performed in binary mode Unregistered bug Connecting with a multi byte character set was unsafe if the database had columns using a different character set 72 Chapter 11 Security in Firebird 2 Summary of Changes Improving security has had a lot of focus in Firebird 2 0 development The following is a summary of the major changes New security database The new security database is renamed as security2 fdb Inside the user authentication table where user names and passwords are stored is now called RDBSUSERS There is no longer a table named users but a new view over RDBSUSERS that is named USERS Through this view users can change their passwords For details of the new database see New Security Database in the section about authentication later in this chapter For instructions on updating previous security databases refer to the section Dealing with the New Security Database at the end of this chapter Better password encryption A Peshkov Password encryption decryption now uses a more secure password hash calculation algorithm Users can modify their own passwords A Peshkov The SYSDBA remains the keeper of the security database However users can now modify their own passwords Non server access to security database is rejected A Peshkov gsec now uses the Services API The server will refuse any access to security2 fdb except through the Services Manager 7
40. or renames it to firebird confnnnn preserves aliases conf or renames it to aliases confnnnn nnnn is the build number of the old installation No attempt is made to uninstall files that were not part of the original installation Shared files such as fbclient dll and gds32 dll will be deleted if the share count indicates that no other application is using them The Registry keys that were created will be removed Installing Superserver from a zip kit The installation of FB 2 0 is similiar in principle to previous versions If you don t have a special setup program it s distributed separately the steps are the following e unzip the archive into a new directory change the current directory to FIREBIRD bin here and below FIREBIRD refers to the direct ory where the v 2 0 files are located run instreg exe instreg exe install It causes the installation path of the directory above to be written into the registry HKLM Software Firebird Project Firebird Server Instances DefaultInstance if you want to register a service also run instsvc exe 111 INSTALLATION NOTES instsvc exe install optionally you may need to run instclient exe to copy fbclient dll or a specially generated clone as gds32 dll to the OS system directory Installing Classic Server from a zip kit To install the CS engine the only difference is the additional switch for instsvc exe instsvc exe install classic Important N
41. pointing node USHORT offset offset to node in page UCHAR data Data can be read from here New flag for the new index structure New flags are added to the header gt pag_flags The flag btr_large_keys 32 is for storing compressed length prefix and record number This meant also that length and prefix can be up to 1 4 of page size 1024 for 4096 page size and is easy extensible in the future without changing disk structure again Also the record number can be easy extended to for example 40 bits Those numbers are stored per 7 bits with 1 bit highest as marker variable length encoding Every new byte that needs to be stored is shifted by 7 Examples 25 is stored as 1 byte 0x19 130 2 bytes 0x82 0x01 65535 3 bytes OXFF OxFF 0x03 Duplicate nodes A new flag is also added for storing record number on every node non leaf pages This speeds up in dex retrieval on many duplicates The flag is btr_all_recordnumber 16 57 Enhancements to Indexing With this added information key lookup on inserts deletes with many duplicates NULLs in foreign keys for example becomes much faster such as the garbage collection Beside that duplicate nodes length 0 don t store their length information 3 bits from the first stored byte are used to determine if this nodes is a duplicate Beside the ZERO LENGTH 4 there is also END LEVEL 1 END_BUCKET 2 ZERO_PREFIX_ZERO_LENGTH 3 and ONE_LENGTH 5 marker Numb
42. publicly available in a subsequent v 2 x release Installer Support for Multiple Server Installations Although the capability to run multiple Firebird servers simultaneously on a single host has been present since Firebird 1 5 we still do not provide the ability to set them up through our installer programs and scripts Support for Databases on Raw Devices During Firebird 2 development a capability to create and access databases on raw devices on POSIX systems was enabled to assist an obscure platform port To date it is undocumented has not been subjected to rigorous QA or field testing and is known to present problems for calculat ing disk usage statistics A Readme text will be made available in the CVS tree for those who wish to give it a try and would like to make a case for its becoming a feature in a future release Bug Reporting and Support If you think you have discovered a bug in this release please make a point of reading the instructions for bug reporting in the article How to Report Bugs Effectively at the Firebird Project website Follow these guidelines as you attempt to analyse your bug 1 Write detailed bug reports supplying the exact server model and build number of your Firebird kit Also provide details of the OS platform Include reproducible test data in your report and post it to our Tracker If you want to start a discussion thread about a bug or an implementation do so by subscribing to the firebird de
43. rdb relation name is a system table from rdbSrelations where rdb system flag 1 New String Size Functions A dos Santos Fernandes Three new functions will return information about the size of strings 1 BIT LENGTH returns the length of a string in bits 2 CHAR LENGTH CHARACTER LENGTH returns the length of a string in characters 3 OCTET LENGTH returns the length of a string in bytes Syntax Pattern These three functions share a similar syntax pattern as follows length function BIT LENGTH CHAR LENGTH CHARACTER LENGTH OCTET LENGTH value expression Example select rdb relation name char length rdb relation name char length trim rdbSrelation_name from rdb relations 65 New Features for Text Data New INTL Interface for Non ASCII Character Sets A dos Santos Fernandes A feature of Firebird 2 is the introduction of a new interface for international character sets Originally described by N Samofatov the new interface features a number of enhancements that have been im plemented by me Architecture Firebird allows character sets and collations to be declared in any character field or variable declara tion The default character set can also be specified at database create time to cause every CHAR VARCHAR declaration that doesn t specifically included a CHARACTER SET clause to use it At attachment time you can specify the character set that th
44. the problems that Microsoft have had with DLL hell it wouldn t make much sense if we contin ued to store the Firebird client library in the system directory Furthermore as we want to allow mul tiple engines to run simultaneously we would be creating our own DLL hell if we continued the prac tice of using the system directory for the client library So from Firebird 1 5 on the client library resides in the bin directory along with all the other binar ies The installer provides the option unchecked to copy the client to the system directory for those who have applications that require to load them from there Registry Key A Registry key has been added and all Firebird 2 0 compliant applications should use this key if they need to read a Registry key to locate the correct version of Firebird that they wish to use The new key is HKEY_LOCAL_MACHINE SOFTWARE Firebird Project Firebird Server Instances Firebird will guarantee that one entry under this key always exists It will be known as 107 INSTALLATION NOTES DefaultInstance and will store the path to the root directory of yes you ve guessed it the default installation Those that don t care about particular installations can always use the default instance to locate the fbcli ent dll Future versions of Firebird will see other entries under Instances Applications will be able to enumer ate the Registry entries to determine which Server instance they wish t
45. 2 Columns can now be used without qualifiers in a higher scope level The current scope level is checked first and ambiguous field checking is done at scope level Examples a I When an alias is present it must be used or no alias at all must be used This query was allowed in FB1 5 and earlier versions SELECT RDBSRELATIONS RDBSRELATION NAME 98 Known Compatibility Issues FROM RDBSRELATIONS R Now the engine will correctly report an error RDB RELATIONS RDB RELATION NAME could not be found that the field Use this preferred SELECT R RDBSRELATION_NAME FROM RDBSRELATIONS R or this statement SELECT RDBSRELATION_NAME FROM RDBSRELATIONS R a 2 The next statement will now use the appropriate FieldID correctly from the subquery and from the updating table UPDATE TableA SET FieldA SELECT SUM A FieldB FROM TableA A WHERE A FieldID TableA FieldID Note Although it is possible in Firebird to provide an alias in an update statement many other data base vendors do not support it These SQL statement syntaxes provide better interchangeability with other SQL database products a 3 This example ran incorrectly in Firebird 1 5 and earlier SELECT RD BSRI R2 FROM JOIN R2 RDBSRE RDBSRE RDBSRE ELATIONS RDBSR ELATION NAME LATION NAME LATIONS ON RDBSRE LATIONS R2 LATION
46. 2 0 0 nnnnn i686 rpmis replaced by FirebirdSS 2 0 0 nnnnn i686 rpm Note For those who in the past have had trouble installing Firebird on Slackware the good news is that the installers in this version do include Slackware support Log in as root or open a root shell In the example filenames replace nnnnn with the build number of the kit you actually have RPM Installer For the RPM installer type Srpm ivh FirebirdCS 2 0 0 nnnnn i686 rpm Installing the Tarball To install the tarball place the tar gz file and type Star xzf FirebirdCS 2 0 0 nnnnn tar gz cd FirebirdCS 2 0 0 nnnnn i686 install sh What the Linux install scripts will do The Linux install scripts will 1 Attempt to stop any currently running server 2 Add the user firebird and the group firebird if they do not already exist 3 Install the software into the directory opt firebird and create links for libraries in usr lib and header files in usr include 4 Automatically add gds db for port 3050 to etc services if the entry does not already exist 5 Automatically add localhost localdomain and HOSTNAME to etc gds hosts equiv a SuperServer only installs a etc rc d init d firebird server start script b Classic server installs a etc xinetd d firebird start script or for older inetd systems adds an 117 INSTALLATION NOTES entry to the etc inetd file 7 Specific to SuSE a new rcfirebird link is created in
47. 3 Security in Firebird 2 Active protection from brute force attack A Peshkov Attempts to get access to the server using brute force techniques on accounts and passwords are now detected and locked out Login with password is required from any remote client Clients making too many wrong login attempts are blocked from further attempts for a period Support for brute force attack protection has been included in both the attachment functions of the Firebird API and the Services API For more details see Protection from Brute force Hacking Vulnerabilities have been closed A Peshkov C Valderrama Several known vulnerabilities in the API have been closed Caution It must be noted that the restoration of the server redirection multi hop capability to Firebird 2 potentially throws up a new vulnerability For that reason it is controlled by a parameter Redirec tion in firebird conf which you should not enable unless you really understand its implications These days the ability to redirect requests to other servers is dangerous Suppose you have one care fully protected firebird server access to which is possible from the Internet In a situation where this server has unrestricted access to your internal LAN it will work as a gateway for incoming requests like irebird your domain com internal server private database fdb Knowing the name or IP address of some internal server on your LAN is enough for an intruder
48. 3 If the RETURNING clause is present then the statement is described as isc_info_sql_stmt_exec_procedure by the API instead of isc_info_sql_stmt_insert so the ex isting connectivity drivers should support this feature automagically 4 Any explicit record change update or delete performed by AFTER triggers is ignored by the RETURNING clause 5 Cursor based inserts INSERT INTO SELECT RETURNING are not supported 6 This clause can return table column values or arbitrary expressions DSQL parsing of table aliases is stricter A Brinkman Alias handling and ambiguous field detecting have been improved In summary 1 When a table alias is provided for a table either that alias or no alias must be used It is no longer valid to supply only the table name 2 Ambiguity checking now checks first for ambiguity at the current level of scope making it valid in some conditions for columns to be used without qualifiers at a higher scope level Examples 1 When an alias is present it must be used or no alias at all is allowed a This query was allowed in FB1 5 and earlier versions SELECT RDBSRELATIONS RDBSRELATION NAME FROM RDBSRELATIONS R but will now correctly report an error that the field RDBSRELATIONS RDBS RELATION NAME could not be found Use this preferred SELECT R RDBSRELATION NAME FROM RDBSRELATIONS R or this statement
49. Commands rece bee eee aai iii tesa eh ese ccenenuvecgteens swadensvecaeaes 84 ISQEL Bugs Fixed inte ette etre det nine tte exer baa eeepc eee E aaea a Ea tes 87 gsec Authentication Manager sssse III eem emen nr nnne 87 PSEC reri ode oi oie ge eee EG tope ego ip ao aapa ee ade aai 88 GFix Server Utility E 88 New Shutdown States Modes ccccceccssesceceeseseecesseeeeeeaseneesesseneeeeasaneesessanees 88 13 External Functions UDEBS eie tetro HUE ERREUR SLE SS aediectons SERER 90 Ability to Signal SQL NULL via a Null Pointer 90 UDF library diagnostic messages improved ssseee 91 UDFs Added and Ch nged nee nee 91 IB UDF rand vs IB_LUDF_srand eeseseseseeseeeee eee 9 IB UDB NO Weis 5 tsececcortt tecese a esee on oben seem debe te dece m veda suatonste 92 General UDF Ch nges ree ee Eee EC CM epo 92 Build Changes REPE 92 14 New Configuration Parameters and Changes sseeeee ee 93 ExternalFileACC sS 2 21 eie ete esee ertet e ed dee oe eee tere ne e dace pee dna 93 Leg acyHash uie acte eereeetteez e te tiere Er tee exi eee TET 93 Iura 93 About M ulti hop ette Cet ere pareat ote ne eene eee nep ete tota deed cuueledett ct 93 Gaudi M P 94 New parameter OldColumnNaming eeeeee II eene 94 UsePrierity Scheduler eterne eterne pedet erede aia del 94 TCPNoNasle has
50. Create incremental backup R database lt fileO gt lt filel gt Restore incremental backup U user User name P password Password Note database may specify a database alias 2 incremental backups of multi file databases are not supported yet 3 stdout may be used as a value of filename for the B option User Manual P Vinkenoog A user manual for NBak NBackup has been prepared It can be downloaded from the documentation area at the Firebird website www firebirdsgl org pdfmanual the file name is Firebird nbackup pdf gbak Backup Porting Restore Utility Content New Switches Changed Behaviours V Horsun The new gbak switch RECREATE DATABASE OVERWRITE pl replaces the old switch making it harder for the unsuspecting to overwrite a database accidentally as could occur with the shortened or long form of the now defunct old switch R EPLACE DATABASE In summary e gbak R ECREATE DATABASE and gbak C REATE DATABASE are now equivalent gbak R ECREATE DATABASE O VERWRITE is equivalent to the old gbak R EPLACE DATABASE 81 Command line Utilities The old gbak R EPLACE_DATABASE is now REP LACE DATABASE That is to say now it will be necessary to include the O VERWRITE flag in order to have gbak re store over an existing database ISQL Query Utility Work on ISQL has involved a lot of bug fixing and the introduction of
51. Developer Country Major Tasks Ann Harrison U S A Frequent technical advisor Jim Starkey U S A Frequent architectural advisor occasional bug fixer Roman Rokytskyy Germany Jaybird implementor and co coordinator Ryan Baldwin U K Jaybird Type 2 driver developer Evgeny Putilin Russian Java stored procedures implementation Federation Carlos Guzman Alvarez Spain Developer and coordinator of NET providers for Fire bird Vladimir Tsvigun Ukraine Developer and coordinator of ODBC JDBC driver for Firebird David Rushby U K Developer and coordinator KInterbase Python interface for Firebird Konstantin Kuznetsov Russian Solaris Intel builds Federation Paul Vinkenoog The Nether Coordinator Firebird documentation project document lands ation writer and tools developer implementor Norman Dunbar U K Documentation writer Pavel Menshchikov Russian Documentation translator Federation Tomneko Hayashi Japan Documentation translator Umberto Mimmo Italy Documentation translator Masotti Olivier Mascia Belgium IBPP C interface developer re implementor of Win32 installation services Oleg Loa Russian Contributor Federation Grzegorz Prokopski Hungary Debian builds 148 Firebird 2 0 Project Teams Developer Country Major Tasks Erik Kunze Germany SINIX Z port raw device enablement Helen Borrie Australia Release notes editor Chief of Thought Police 149 Chapter 19 Appendix to Firebird 2
52. ECT Statement amp Expression Syntax sss eene 42 6 New Reserved Words and Changes eceeeeeeeeeeeeeceeecececeeececececececeeeseeeeeeeseeeeeeeeeeeeeees 44 Newly Reserved Words 5 12 eoi ereee tere ote tee ee eene es REEE EE En A FE gehe oH ETIES 44 Changed from Non reserved to Reserved ssseseee 44 Keywords Added as Non reserved sssssssseeeeeeeememenene 44 Keywords No Longer Reserved sssssseeeeeeeenemememememememenenen 45 No Longer Reserved as Keywords seseeeee eee 45 7 Stored Procedure Language PSQL menaire nnie i a a a i e a a 46 PSOL Enhancement anann na prete N Seas Wee dn R 46 Context Variable ROW COUNT Enhanced eee eee 46 Explicit CUSTS E E 46 Defaults for Stored Procedure Arguments eese 48 LEAVE label Syntax Support onenn ern sin keinent ae ation ERR ESS 50 OLD Context Variables Now Read only see 51 PSOE Stack Trace iretur Eit eoe see aee e ete d ore s iva aee e dE a Eae ge pd ee et 51 Call a UDF as a Void Function Procedure sssssssesseeee 53 8 Enhancements to Indexing sss 54 252 byte index length limit is gone see 54 Expression Indexes J iie eec eee thee e DECRE EC teg 54 Changes to Null keys handling see eene 55 Improved Index Compression osiris rren e teen etnies tenebre etes 55 Selectivity Maintenance per Segment 00 0 0
53. ELECT COUNT FROM aTable or other table scanning query from a user as occurs in Classic and in versions of InterBase prior to v 6 0 This earlier GC mechanism is known as cooperative garbage col lection Background GC also averts the possibility that those pages will be missed because they are seldom read A sweep of course would find those unused record versions and clear them but the next sweep is not necessarily going to happen soon A further benefit is the reduction in I O because of the high 5 New in Firebird 2 0 er probability that subsequently requested pages still reside in the buffer cache Between the point where the engine notifies the garbage collector about a page containing unused ver sions and the point when the garbage collector gets around to reading that page a new transaction could update a record on it The garbage collector cannot clean up this record if this later transaction number is higher than the Oldest Snapshot or is still active The engine again notifies the garbage col lector about this page number overriding the earlier notification about it and the garbage will be cleaned at some later time In Firebird 2 0 Superserver both cooperative and background garbage collection are now possible To manage it the new configuration parameter GCPolicy was introduced It can be set to cooperative garbage collection will be performed only in cooperative mode like Classic and the engine will
54. EPI aae Oaea aea 133 Crash Conditions eee e eee eee e e iian ra iiaia tree aeneo ecd 134 Remote Interface Bugs 4i uie ee a Ea ESI Re sade oee 136 Indexing amp Optimization e cete eet eere peer eee EVDAR 138 NMiUlNE rab ties TET I D LI D OQ E E 139 RO EA oT e T 139 International Character Set Bugs ssee eee 140 SOL Privileges s ertet ehe rheet ee ree ea HERE Pede Prae et E vais davveneescd 141 WDE Bugs EE 142 OAK qe E 142 rA D POA ue eee te NEED E EE ERREUR EEREI UE 144 DICT EP RE 144 DB dios CT 145 Linux Install S 5 2 e rH eret 145 Code Cleansup ueni pettte rne eet tete Fee ee ate epe EEA 145 vii Firebird 2 0 Release Notes Platform specifie sss iacente ijiner eee ger epe nete eee tte senigata ra iS 145 18 Firebird 2 0 Project Teams e retener Renee tette teen EEEE aT aED 147 19 Appendix to Firebird 2 Release Notes ssseeeee eene 150 Security Upgrade Script tinere ed n et eget ite tenes tore o ae eoi etre dte bend 150 viii List of Figures 8 1 Existing structure ODS10 and lower sse nennen eene nnne enne 56 8 2 New ODS II str ct te 2 5 metet etse ete VENE ee Sencha ciet oos ce adea ENE ANATA aad 57 8 3 Example data x size in x bytes ornoen rae eiia r E a AEE 58 9 4 Examples dar d e ed po de e eei eh eee A 59 1X List of Tables 18 1 Firebird Development Teams Chapter 1 Ge
55. Features for Text Data SQL gt SQL gt select c upper c from t C UPPER MoD w Dom D In FB 2 0 the result is C UPPER Ooo 9 Eh pg D gt Maximum String Length In FB 1 5 X the engine does not verify the logical length of multi byte character set MBCS strings Hence a UNICODE_FSS field takes three times as many characters as the declared field size three being the maximum length of one UNICODE_FSS character This has been retained for compatibility for legacy character sets However new character sets UTF8 for example do not inherit this limitation sqisubtype and Attachment Character Set When the character set of a CHAR or VARCHAR column is anything but NONE or OCTETS and the attachment character set is not NONE the sglsubtype member of an XSQLVAR pertaining to that column now contains the attachment connection character set number instead of the column s char acter set Enhancements for BLOBs Several enhancements have been added for text BLOBs COLLATE clauses for BLOBs A DML COLLATE clause is now allowed with BLOBs Example select blob column from table where blob column collate unicode foo 67 New Features for Text Data Full equality comparisons between BLOBs Comparison can be performed on the entire content of a text BLOB Character set conversion for BLOBs Conversion between character sets is now possible when assigning to a BLOB from a string or an
56. INPUT command to load script B an so on Isql doesn t check for direct or in direct recursion thus if the programmer makes a mistake and script A loads itself or loads script B that in turn loads script A again isql will run until it exhaust memory or an error is returned from the database at whose point bail if activated will stop all activity DML errors will be caught when being prepared or executed depending on the type of error In many cases isql will return the line number of a DML statement that fails during execution of a script More about error line numbers DDL errors will be caught when being prepared or executed by default since isql uses AUTODDL ON by default However if AUTO DLL is OFF the server only complains when the script does an explicit COMMIT and this may involve several SQL statements 82 Command line Utilities The feature can be enabled disabled interactively or from a script by means of the command SET BAIL ON OFF As is the case with other SET commands simply using SET BAIL will toggle the state between activated and deactivated Using SET will display the state of the switch among many others Even if BAIL is activated it doesn t mean it will change isql behavior An additional requirement should be met the session should be non interactive A non interactive session happens when the user calls isql in batch mode giving it a script as input Example isql b i my fb sql o re
57. K COLLATION COMMENT DIFFERENCE IIF NEXT SCALAR_ARRAY SEQUENCE RESTART RETURNING 44 New Reserved Words and Changes Keywords No Longer Reserved ACTION RESTRICT ROLE YEARDAY FREE_IT TYPE No Longer Reserved as Keywords BASENAME GROUP COMMIT WAIT NUM LOG BUFS CACHE LOGFILE RAW PARTITIONS CHECK POINT LEN LOG BUF SIZE 45 Stored Procedure Language PSQL PSQL Enhancements The following enhancements have been made to the PSQL language extensions for stored procedures and triggers Context Variable ROW_COUNT Enhanced D Yemanov ROW_COUNT has been enhanced so that it can now return the number of rows returned by a SE LECT statement For example it can be used to check whether a singleton SELECT INTO statement has performed an assignment BEGIN SELECT COL FROM TAB INTO VAR IF ROW_COUNT 0 THEN EXCEPTION NO_DATA_FOUND END See also its usage in the examples below for explicit PSQL cursors Explicit Cursors D Yemanov It is now possible to declare and use multiple cursors in PSQL Explicit cursors are available in a DSQL EXECUTE BLOCK structure as well as in stored procedures and triggers Syntax pattern DECLARE VARIABLE lt cursor_name gt CURSOR FOR lt select_statement gt OPEN lt cursor_name gt FETCH cursor name INTO var name var name CLOSE cursor name Examp
58. L_disconnect_database was overwriting the Quiet flag permanently fixed by M Penchev C Valderrama SF 1208932 SHOW GRANT did not distinguish object types fixed by C Valderrama SF 494981 Bad exception report fixed by C Valderrama SF 450404 ISQL would uppercase role in the command line fixed by C Valderrama Various not registered 1 Fix for the b Bail On Error option when SQL commands are issued and no db connection ex ists yet 2 Applied Miroslav Penchev s patch for bug with Q always returning 1 to the operating system discovered by Ivan Prenosil fixed by M Penchev C Valderrama Not registered Metadata extraction for triggers check constraints and views with check option was wrong fixed by C Valderrama D Yemanov International Character Set Bugs SF 1016040 Missing external libraries would cause an engine exception fixed by A dos Santos Fernandes Not registered 1 Charset collation issues for expression based view columns 2 Lost charset collation for local PSQL variables 140 Bugs Fixed fixed by D Yemanov Not registered Comparisons between strings in NONE and another character set would cause an error fixed by D Yemanov A dos Santos Fernandes SF 1244126 There was a problem updating some text BLOBs when connected with character set NONE fixed by A dos Santos Fernandes SF 1242379 Applying a collation could change a VARCHAR s length fixed by A dos Santos Fernandes
59. NAME RDBSRELATIONS RDBSRELATION NAM E If RDB RELATIONS contained 90 rows it would return 90 90 8100 rows but in Firebird 2 0 it will correctly return 90 rows b 1 This would fail in Firebird 1 5 but is possible in Firebird 2 0 SELECT SELECT RD FROM R BSRELATION NAME FROM RDBSDATABASE DBSRELATIONS b 2 Ambiguity checking in subqueries This would run on Firebird 1 5 without reporting an ambiguity but will report it in Firebird 2 0 99 Known Compatibility Issues SELECT SELECT FIRST 1 RDBSRELATION_NAME FROM RDBSRELATIONS R1 JOIN RDBSRELATIONS R2 ON R2 RDBSRELATION NAME R1 RDBSRELATION NAME FROM RDBSDATABASE Multiple Hits to Same Column Now Illegal It is no longer allowed to make multiple hits on the same column in an INSERT or UPDATE state ment Thus a statement like INSERT INTO T A B A or UPDATE T SETA x B y A z will be rejected in Firebird 2 n even though it was tolerated in InterBase and previous Firebird ver sions Query Plans Stricter validation of user specified plans User specified plans are validated more strictly than they were formerly If you encounter an ex ception related to plans e g Table T is not referenced in plan it will be necessary to inspect your procedure and trigger sources and adjust the plans to make them semantically cor rect Important Such
60. NG btr_prefix_total sum of all prefixes on page USHORT btr relation relation id for consistency USHORT btr length length of data in bucket UCHAR btr id index id for consistency UCHAR btr level index level 0 leaf struct btn btr_nodes 1 node struct btn UCHAR btn_prefix size of compressed prefix UCHAR btn_length length of data in node UCHAR btn_number 4 page or record number UCHAR btn data 1 end marker END_BUCKET or END_LEVEL These are in place of record number for leaf nodes and in place of page number for non leaf nodes If the node is a END_BUCKET marker then it should contain the same data as the first node on the next sibling page On an END_LEVEL marker prefix and length are zero thus it contains no data Also every first node 56 Enhancements to Indexing on a level except leaf pages contains a degeneration zero length node Figure 8 2 New ODS11 structure jump info struct IndexJumpInfo USHORT firstNodeOffset offset to first node in page USHORT jumpAreaSize size area before a new jumpnode is made UCHAR Jumpers nr of jump nodes in page with a maximum of 255 h jump node struct IndexJumpNode UCHAR nodePointer pointer to where this node can be read from the page USHORT prefix length of prefix against previous jump node USHORT length length of data in jump node together with prefix this is prefix for
61. OMMIT 2 save users data INSERT INTO UTMP USER NAME SYS USER NAME GROUP NAME 150 Appendix to Firebird 2 Release Notes UID GID PRIVILEGE COMMENT FIRST NAME MIDDLE NAME LAST_NAME PASSWD SELECT USER NAME SYS USER NAME GROUP NAME UID GID PRIVILEGE COMMENT FIRST NAME MIDDLE NAME LAST NAME PASSWD FROM USERS COMMIT 3 drop old tables and domains DROP TABLE USERS DROP TABLE HOST INFO COMMIT DROP DOMAIN COMMENT DROP DOMAIN NAME PART DROP DOMAIN GID DROP DOMAIN HOST KEY DROP DOMAIN HOST NAME DROP DOMAIN PASSWD DROP DOMAIN UID DROP DOMAIN USER NAME DROP DOMAIN PRIVILEGE COMMIT 4 create new objects in database CREATE DOMAIN RDBSCOMMENT AS BLOB SUB TYPE TEXT SEGMENT SIZE 80 CHARACTER SET UNICODE_FSS CREATE DOMAIN RDBSNAME_ PART AS VARCHAR 32 CHARACTER SET UNICODE FSS DEFAULT UNICODE FSS CREATE DOMAIN RDBSGID AS INTEGER CREATE DOMAIN RDBSPASSWD AS VARCHAR 64 CHARACTER SET BINARY CREATE DOMAIN RDBSUID AS INTEGER
62. OR EQUENCE DEX LATION ECURITY CLASS NDQNOADHNA N OLE HARACTER SET OI not implemented because this type is hidden 19 Data Definition Language DDL Extensions to CREATE VIEW Specification D Yemanov FIRST SKIP and ROWS syntaxes and PLAN and ORDER BY clauses can now be used in view spe cifications From Firebird 2 0 onward views are treated as fully featured SELECT expressions Consequently the clauses FIRST SKIP ROWS UNION ORDER BY and PLAN are now allowed in views and work as expected Syntax For syntax details refer to Select Statement amp Expression Syntax in the chapter about DML RECREATE TRIGGER Statement Implemented D Yemanov The DDL statement RECREATE TRIGGER statement is now available in DDL Semantics are the same as for other RECREATE statements Usage Enhancements The following changes will affect usage or existing pre Firebird 2 workarounds in existing applica tions or databases to some degree Creating Foreign Key Constraints No Longer Requires Exclusive Access V Horsun Now it is possible to create foreign key constraints without needing to get an exclusive lock on the whole database Changed Logic for View Updates Apply NOT NULL constraints to base tables only ignoring the ones inherited by view columns from domain definitions Declare BLOB Subtypes by Known Descriptive Identifiers A Peshkov C Valderrama
63. P_NODELAY Removed or Deprecated Parameters CreatelnternalWindow D Yemanov The option CreateInternalWindow is no longer required to run multiple server instances and it has been removed 94 New Configuration Parameters and Changes DeadThreadsCollection is no longer used A Peshkov The DeadThreadsCollection parameter is no longer used at all Dead threads are now efficiently re leased on the fly making configuration unnecessary Firebird 2 0 silently ignores this parameter 95 Chapter 15 Known Compatibility Issues D Yemanov This chapter is intended as a set of alerts to those who are migrating Firebird 1 0 or 1 5 databases to Firebird 2 0 It should be studied before attempting to install any servers The FIREBIRD Variable FIREBIRD is an optional environment variable that provides a system level pointer to the root direct ory of the Firebird installation If it exists it is available everywhere in the scope for which the vari able was defined The FIREBIRD variable is NOT removed by scripted uninstalls and it is not updated by the installer scripts If you leave it defined to point to the root directory of a v 1 5 x installation there will be situ ations where the Firebird engine command line tools cron scripts batch files installers etc will not work as expected If the Windows installer program finds a value for FIREBIRD it will make that path the default location that it offers inste
64. Previously the only allowed syntax for declaring a blob filter was declare filter name input type number output type number entry point function in library module name library name The alternative new syntax is declare filter name input type mnemonic output type lt mnemonic gt 20 Data Definition Language DDL entry_point lt function_in_library gt module_name lt library_name gt where lt mnemonic gt refers to a subtype identifier known to the engine Initially they are binary text and others mostly for internal usage but an adventurous user could write a new mnemonic in rdb types and use it since it is parsed only at declaration time The engine keeps the numerical value Remember only negative subtype values are meant to be defined by users To get the predefined types do I select RDBSTYPE RDBSTYPE NAME RDBS SYSTEM FLAG from rdbStypes where rdbSfield name RDBS FIELD SUB TYPE I RDBSTYPE RDBSTYPE NAME RDBS SYSTEM FLAG INARY ES SUMMARY FORMAT TRANSACTION DESCRIPTION EXTERNAL FILE DESCRIPTION cO 1O0 Y 014 C0 I9 IS CO Jj Dp zi Q Examples Original declaration declare filter pesh input_type 0 output_type 3 entry_point f module_name p Alternative declaration declare filter pesh input_type binary output_type acl entry_point f module_name p Declar
65. R SQL gt INSERT INTO tab VALUES 2000000000 SQL gt COMMIT SQL gt ALTER TABLE tab ALTER i TYPE VARCHAR 5 Statement failed SQLCODE 607 unsuccessful metadata update New size specified for column I must be at least 11 characters Le it would need potentially 10 characters for the numerals and one for the negative sign SQL gt ALTER TABLE tab ALTER i TYPE VARCHAR 9 This command should fail with the same error but it did not which could later lead to unreadable data SQL gt SELECT FROM tab Statement failed SQLCODE 413 conversion error from string 2000000000 fixed by C Valderrama Not registered There were some rounding problems in date time arithmetic fixed by N Samofatov Not registered Line numbers in DSQL parser were being miscounted when multi line literals and identifiers were used 131 Bugs Fixed fixed by N Samofatov SF 784121 Some expressions in outer join conditions were causing problems fixed by C Valderrama Not registered There were some dialect specific arithmetic bugs Dialect 1 1l 1 5 0 5 did not work 2 avg 1 5 did not work 3 5 1 5 produced an INT result instead of DOUBLE PRECISION 4 sum 1 5 produced a NUMERIC 15 2 result instead of DOUBLE PRECISION 5 1 5 did not work Dialect 3 e 1 5 0 5 and 1 5 0 5 were not forbidden but they should have been fixed by D Yemanov SF 1250150 There was a situation wh
66. R SELECT cursor are prohibited Attempts to open a cursor that is already open or to fetch from or close a cursor that is already closed will fail All cursors which were not explicitly closed will be closed automatically on exit from the current PSQL block procedure trigger The ROW COUNT system variable can be used after each FETCH statement to check whether any row was returned Defaults for Stored Procedure Arguments V Horsun Defaults can now be declared for stored procedure arguments The syntax is the same as a default value definition for a column or domain except that you can use in place of DEFAULT keyword Arguments with default values must be last in the argument list that is you cannot declare an argu ment that has no default value after any arguments that have been declared with default values The caller must supply the values for all of the arguments preceding any that are to use their defaults For example it is illegal to do something like this supply argl arg2 miss arg3 set arg4 Substitution of default values occurs at run time If you define a procedure with defaults say P1 call it from another procedure say P2 and skip some final defaulted arguments then the default values for P1 will be substituted by the engine at time execution P1 starts This means that if you change the default values for P1 it is not necessary to recompile P2 However it is still necessary to disc
67. Release Notes Security Upgrade Script A Peshkov Script security_database sql The contents of this file are subject to the Initial Developer s Public License Version 1 0 the License you may not use this file except in compliance with the License You may obtain a copy of the License at http www ibphoenix com main nfs a ibphoenix amp page ibp idpl Software distributed under the License is distributed AS IS WITHOUT WARRANTY OF ANY KIND either express or implied See the License for the specific language governing rights and limitations under the License The Original Code was created by Alex Peshkov on 16 Nov 2004 for the Firebird Open Source RDBMS project Copyright c 2004 Alex Peshkov and all contributors signed below All Rights Reserved Contributor s 1 temporary table to alter domains correctly CREATE TABLE UTMP USER NAME VARCHAR 128 CHARACTER SET ASCII SYS USER NAME VARCHAR 128 CHARACTER SET ASCII GROUP NAME VARCHAR 128 CHARACTER SET ASCII UID INTEGER GID INTEGER PASSWD VARCHAR 64 CHARACTER SET BINARY PRIVILEGE INTEGER COMMENT BLOB SUB TYPE TEXT SEGMENT SIZE 80 CHARACTER SET UNICODE FSS FIRST NAME VARCHAR 32 CHARACTER SET UNICODE FSS DEFAULT UNICODE FSS MIDDLE NAME VARCHAR 32 CHARACTER SET UNICODE FSS DEFAULT UNICODE FSS LAST NAME VARCHAR 32 CHARACTER SET UNICODE FSS DEFAULT UNICODE FSS C
68. S RDER BY 9 O hj E Parameters and Ordinal Sorts a Gotcha According to grammar rules since v 1 5 ORDER BY lt value_expression gt is allowed and lt value_expression gt could be a variable or a parameter It is tempting to assume that ORDER BY lt degree_number gt could thus be validly represented as a replaceable input parameter or an expression containing a parameter However while the DSQL parser does not reject the parameterised ORDER BY clause expression if it resolves to an integer the optimizer requires an absolute constant value in order to identify the pos ition in the output list of the ordering column or derived field If a parameter is accepted by the parser the output will undergo a dummy sort and the returned set will be unsorted NEXT VALUE FOR Expression Syntax D Yemanov Added SQL 99 compliant NEXT VALUE FOR lt sequence_name gt expression as a synonym for GEN_ID lt generator name gt 1 complementing the introduction of CREATE SEQUENCE syntax as the SQL standard equivalent of CREATE GENERATOR Examples 1 SELECT GEN ID S EMPLOYEE 1 FROM RDBSDATABASE INSERT INTO EMPLOYEE ID NAME VALUES NEXT VALUE FOR S EMPLOYEE John Smith 38 Data Manipulation Language DML Note 1 Currently increment step values not equal to 1 one can be used only by calling the GEN_ID function Future versions are exp
69. S FIXES e ede e tede e ede Rr ee eed 71 11 Security 1n Firebird 2 ree ee Ga ere he M denepa 73 Summary of Changes et eraot te eet ARN A RID eX OR HERR et PP et 73 New security database e eei eerte eere eene tentent tke eerie eee eee 73 Better password encryption ssseseeeee III eene nren ener eren 73 Users can modify their own passwords sseee ee 73 Non server access to security database is rejected sseeeeeee 73 Active protection from brute force attack ssssee 74 Vulnerabilities have been closed ss ee 74 Details of the Security Changes in Firebird 2 0 sssseeee 74 Authentication ite eee e eere eet coud thes tele aee lebte Woes deals ledere p i En bere 75 gsectv Firebird 2 ied ene eh tiet ep Ee EET 76 Protection from Brute force Hacking seeee ee 76 Classic Setveron POSIX 30s sac eA A ed eb ee 76 Dealing with the New Security Database ssese TI Doing the Security Database Upgrade eeeee TI 12 Command Ime Utilities retired etai oer eee ceb bre ese NY eee citur e eee eee bie gode eh 79 Backup Tools nee tere dM eese tte edd ee de eset te eed te neta et pe edlen 79 New On line Incremental Backup sseseeee eene 79 gbak Backup Porting Restore Utility eesee 81 ISQL Query BTE E 82 NEW Switches osne ete t eee aa eee LP IE E GR Eee PEEL Re LEER eee e enge 82 New
70. S version supports services you will be asked to choose whether to run Firebird as a service or as an application Unless you have a com pelling need to run the server as an application choose service 110 INSTALLATION NOTES Manual or automatic With the automatic option Firebird will start up whenever you boot the host machine With the manual option you can start the server on demand from the Services applet in the Settings Control Panel Administration Tools selection Use Control Panel Applet Superserver only If Superserver is being installed you will see an option to Install Control Panel applet It s a good idea to keep this as it places an applet in the Control Panel from which you can stop and re start the server Eventually the dialogs will stop you will press Install and the server will either silently start the server if you requested it or prompt you for permission to reboot Reboot will be needed if the in staller was unable to update a DLL due to its being already loaded when the installer started up Uninstallation If you are going to uninstall Firebird first shut down all connections to databases and then if you are running Superserver shut down the server The Firebird uninstall routine run from Add Remove Pro grams in the Control Panel preserves and renames the following key files preserves security2 fdb or renames it to security2 fbnnnn preserves firebird log preserves firebird conf
71. SC USHORT const ISC UCHAR ISC STATUS isc que events ISC STATUS isc db handle ISC LONG short const ISC SCHAR ISC EVENT CALLBACK void It may cause a compile time incompatibility as older event handling programs cannot be com piled if they use a bit different signature for a callback routine e g void instead of const char asthe last parameter Windows Specific Issues For installing configuring and connecting to Windows servers be aware of the following issues Windows Local Connection Protocol with XNet The transport internals for the local protocol have been reimplemented XNET instead of IPServer With regard to the local protocol the new client library is therefore incompatible with older servers and older client libraries are incompatible with the Firebird 2 servers If you need to use the local protocol please ensure your server and client binaries have exactly the same version numbers Client Impersonation No Longer Works WNET a k a NetBEUI Named Pipes protocol no longer performs client impersonation For more information refer to Change to WNET Protcol in the chapter about new features 103 Known Compatibility Issues Interactive Option Added to instsvc exe D Yemanov The optional switch i nteractive has been implemented in instsvc exe to enable an interactive mode for LocalSystem services For v 1 5 it was required as Allow service to interact with desktop to run t
72. SSWD to be RDBSPASSWD RDBSPASSWD NOT NULL Caution with LegacyHash As long as you configure LegacyHash 1in firebird conf Firebird s security does not work completely To set this right it is necessary to do as follows 1 Change the SYSDBA password 2 Have the users change their passwords in 2 0 each user can change his or her own password 3 Set LegacyHash back to default value of 0 or comment it out 4 Stop and restart Firebird for the configuration change to take effect 78 Chapter 12 Command line Utilities Backup Tools Firebird 2 brings plenty of enhancements to backing up databases a new utility for running on line in cremental backups and some improvements to gbak to avoid some of the traps that sometimes befall end users New On line Incremental Backup N Samofatov Fast on line page level incremental backup facilities have been implemented The backup engine comprises two parts NBak the engine support module NBackup the tool that does the actual backups Nbak The functional responsibilities of NBAK are 1 to redirect writes to difference files when asked ALTER DATABASE BEGIN BACKUP state ment 2 to produce a GUID for the database snapshot and write it into the database header before the AL TER DATABASE BEGIN BACKUP statement returns 3 to merge differences into the database when asked ALTER DATABASE END BACKUP state ment 4 to mark p
73. Services API to Classic is Complete eeeeeee 6 Lock Timeout for WAIT Transactions 6 New Implementation of String Search Operators seseeeR 7 Reworking of Updatable Views sseee eee nemen 7 Additional Database Shutdown Modes Introduced seeeess 7 UDFs Improved re NULL Handling eeeee III 8 Signallins SQL NUL PEE 8 Run time Checking for Concatenation Overflow cccccccccececccecececececeeeeeeeeeeeees 8 Changes to Synchronisation Logic eseee eene 8 Support for 64 bit Platforms 5 2 2 2 2 aE te etr ee eee dete nee dores reed ee 9 Record Enumeration Limits Increased esseeeeee 9 Debugging Improvements srne oe E ae EE aD EEE EERE Sieta 9 Improved Reporting from Bugchecks sseeee eee 9 Updated Internal Structure Reporting 2 0 02 ccc cecececececececececeeeeeseceeeeeeeeeees 9 New Debug Logging Facilities see eene 9 Didgnostic Enhancement 5 22 2 eolit teret eee tener ee edet ede eee pe dee ade t eges ipi 9 Improved Connection Handling on POSIX Superserver seeeeese 9 PSQL Invariant Tracking Reworked eeeee 10 ROLLBACK RETAIN Syntax Support sseeee eene 10 No More Registry Search on Win32 Servers sssseeee 10 More Optimizer Improvements sesseee eI Ie eene enne 10 ODS Changes iei reete caevatosatvened Dres
74. T It serves exactly the same goal to provide an efficient way to connect to server located on the same machine as the connecting client without a remote node name in the connection string The new im plementation is different and addresses the known issues with the old protocol Like the old PServer implementation the XNET implementation uses shared memory for inter process communication However XNET eliminates the use of window messages to deliver attach ment requests and it also implements a different synchronization logic Benefits of the XNET Protocol over PServer Besides providing a more robust protocol for local clients the XNET protocol brings some notable benefits New in Firebird 2 0 it works with Classic Server it works for non interactive services and terminal sessions e it eliminates lockups when a number of simultaneous connections are attempted Performance The XNET implementation should be similar to the old PServer implementation although XNET is expected to be slightly faster Disadvantages The one disadvantage is that the XNET and PServer implementations are not compatible with each other This makes it essential that your fbclient dll version should match the version of the server bin aries you are using fbserver exe or fb_inet_server exe exactly It will not be possible to to establish a local connection if this detail is overlooked A TCP localhost loopback connection via an ill match
75. TCP IP buffer size larger than 32 Kb was not being processed correctly fixed by A Peshkov Not registered The NO_NAGLE option was working improperly fixed by F Polizo A Peshkov Not registered NO_NAGLE and KEEPALIVE socket options were not enabled for CS builds 136 Bugs Fixed fixed by D Yemanov SF 1385092 A TCP IP connection would appear to freeze the Superserver if it was disconnec ted abnormally while a large packet e g a BLOB or a large SQL request was being passed across the interface This was a long standing InterBase Firebird bug in the implementation of the protocol layer for Su perserver on Windows Borland invented two different thread management strategies one for TCP IP and one for the other protocols that only Windows supports i e Named Pipes sometimes referred to as NetBEUT and the PServer local connection This bug occurred only with TCP IP connections For TCP IP a multiplexing loop main server loop which is common for all ports receives API packets from clients creates requests and sends them to threads for processing When it detects an in coming packet it starts to receive it from the port Before this fix it needed the entire API packet to come at once However in the course of converting a packet to a request done by the XDR protocol in cases where the size of the API packet happened to be greater than that of the network packet the server had to wait for the next network packet
76. WAIT mode by making provision to set a finite time interval to wait for the concurrent transactions If the timeout has passed an error isc lock timeout is reported Timeout intervals are specified per transaction using the new TPB constant isc tpb lock timeout in the API or in DSQL the LOCK TIMEOUT value clause of the SET TRANSACTION statement New in Firebird 2 0 New Implementation of String Search Operators N Samofatov 1 The operators now work correctly with BLOBs of any size Issues with only the first segment be ing searched and with searches missing matches that straddle segment boundaries are now gone 2 Pattern matching now uses a single pass Knuth Morris Pratt algorithm improving performance when complex patterns are used 3 The engine no longer crashes when NULL is used as ESCAPE character for LIKE Reworking of Updatable Views D Yemanov A reworking has been done to resolve problems with views that are implicitly updatable but still have update triggers This is an important change that will affect systems written to take advantage of the undocumented mis behaviour in previous versions For details see the notes in DDL Migration Issues in the Compatibility chapter of these notes Additional Database Shutdown Modes Introduced N Samofatov Single user and full shutdown modes are implemented using new state parameters for the g ix shut and g ix online commands Syntax Pa
77. a few new useful features One trick to note is that CHAR and VARCHAR types defined in character set OCTETS alias BIN ARY now display in hex format Currently this feature cannot be toggled off New Switches The following command line switches were added b ail Bail out D Ivanov C Valderrama Command line switch b to instruct isql to bail out on error when used in non interactive mode re turning an error code to the operating system When using scripts as input in the command line it may be totally unappropriate to let isql continue executing a batch of commands after an error has happened Therefore the b ail option will cause script execution to stop at the first error it detects No further statements in the input script will be ex ecuted and isql will return an error code to the operating system Most cases have been covered but if you find some error that is not recognized by isql you should inform the project as this is a feature in progress Currently there is no differentiation by error code any non zero return code should be interpreted as failure Depending on other options like o m and m2 isql will show the error message on screen or will send it to a file Some Features Even if isql is executing nested scripts it will cease all execution and will return to the operating system when it detects an error Nested scripts happen when a script A is used as isql input but in turn A contains an
78. abels and terminated in Java style The purpose is to stop execution of the current block and unwind back to the specified la bel After that execution resumes at the statement following the terminated loop Syntax pattern lt label_name gt lt loop_statement gt LEAVE label name where loop statement is one of WHILE FOR SELECT FOR EXECUTE STATEMENT Examples 1 FOR SELECT COALESCE RDBSSYSTEM_ FLAG 0 RDBSRELATION NAME FROM RDBSRELATIONS ORDER BY 1 INTO RTYPE RNAME DO BEGIN IF RTYPE 0 THEN SUSPEND ELSE LEAVE exits current loop END 2 CNT 100 nils WHILE CNT gt 0 DO BEGIN IF CNT 50 THEN LEAVE L1 exists WHILE loop CNT CNT 1 END 50 Stored Procedure Language PSQL STMT1 SELECT RDBSRELATION_NAME FROM RDBSRELATIONS ELLs FOR EXECUTE STATEMENT STMT1 INTO RNAME DO BEGIN STMT2 SELECT RDBSFIELD NAME FROM RDBSRELATION_FIELDS WHERE RDBSRELATION NAME L2 FOR EXECUTE STATEMENT STMT2 RNAME INTO FNAME BEGIN IF RNAME RDBSDATABASE THEN AVE L1 exits the outer loop ELSE IF RNAME RDBSRELATIONS THEN AVE L2 exits the inner loop ELSE SUSPEND OF EN Note Note that LEAVE without an explicit la
79. ad of c Program Files Firebird Firebird_2_0 Unless you are very clear about the effects of having a wrong value in this variable you should re move or update it before you begin installing Firebird 2 0 After doing so you should also check that the old value is no longer visible in the workspace where you are installing Firebird use the SET FIREBIRD command in a Windows shell or printenv FIREBIRD ina POSIX shell Security in Firebird 2 All Platforms Be aware of the following changes that introduce incompatibilities with how your existing applica tions interface with Firebird s security Direct connections to the security database are no longer allowed Apart from the enhancement this offers to server security it also isolates the mechanisms of au thentication from the implementation User accounts can now be configured only by using the Services API or the gsec utility For backing up the security database the Services API is now the only route You can employ the se rvice hostname service mgr switch when invoking the gbak utility for this purpose Non SYSDBA users no longer can see other users accounts in the security database A non privileged user can retrieve or modify only its own account and it can change its own pass word Remote attachments to the server without a login and password are now prohibited 96 Known Compatibility Issues For attachments to Superserver even root trying to connect loc
80. ages written by the engine with the current SCN page scan counter value for the data base 5 to increment SCN on each change of backup state The backup state cycle is nbak state normal gt nbak state stalled gt nbak state merge gt nbak state normal e In normal state writes go directly to the main database files n stalled state writes go to the difference file only and the main files are read only In merge state new pages are not allocated from difference files Writes go to the main database 79 Command line Utilities files Reads of mapped pages compare both page versions and return the version which is fresher because we don t know if it is merged or not Note This merge state logic has one quirky part Both Microsoft and Linux define the contents of file growth as undefined i e garbage and both zero initialize them This is why we don t read mapped pages beyond the original end of the main database file and keep them current in difference file until the end of a merge This is almost half of NBak fetch and write logic tested by using modified PIO on existing files containing garbage NBackup The functional responsibilities of NBackup are l to provide a convenient way to issue ALTER DATABASE BEGIN END BACKUP 2 to fix up the database after filesystem copy physically change nbak state diff to nbak state normal in the database header 3 to create and restore incremental backups Inc
81. ails see the document README Win32LibraryInstallation txt which is located in doc Cleaning up release candidate installs It should be noted that the installer removes fbclient dll from the system directory if the file is found there The installer also removes any deprecated HKLM Software Firebird Registry keys 108 INSTALLATION NOTES Using the Win32 Firebird Installer Important Don t overlook the need to have the Microsoft Visual C and Visual C runtimes msvert dll and msvcpp60 dll respectively present in the system directory of all Windows servers and clients in cluding Windows Embedded installations For your convenience copies of these libraries will be placed in the bin directory of the Firebird install However you should check first whether later versions of these libraries are already present Don t overwrite later versions This is really the easy part the actual install Just run the executable and respond to the dialogs After you have answered a few dialogs about licensing and installation notes you should see one where you decide on the location of the Firebird root directory Installation Root directory The installer should be showing c Program Files Firebird Firebird_2_0 by default If you de cide not to use the default root location browse to a location you have pre created or just type in the full path and let the installer find it The path you type in doesn t have to ex
82. ally without localhost in the database file string will be rejected by the remote interface if a correct login is not supplied Embedded access without login password works fine On Windows authentication is bypassed On POSIX the Unix user name is used to validate access to database files The security database is renamed to security2 fdb If you upgrade an existing installation be sure to upgrade the security database using the provided script in order to keep your existing user logins Before you begin the necessary alterations to commission an existing security database on the Firebird 2 0 server you should create a gbak backup of your old security fdb from v 1 5 or isc4 gdb from v 1 0 using the old server s version of gbak and then restore it using the Firebird 2 0 gbak Important You must make sure that you restore the security database to have a page size of at least 4 Kb The new security2 fdb will not work with a smaller page size Warning A simple cp security fdb security2 fdb will make it impossible to attach to the firebird server For more details see the notes in the chapter on security New Security Features Also read the file security_database txt in the upgrade directory beneath the root directory of your installa tion SQL Migration Issues DDL Views made updatable via triggers no longer perform direct table operations In former versions a naturally updatable view with tri
83. anager Not registered Incorrect encryption of password when the Services Manager was invoked by the Embedded client fixed by A Peshkov GFix Bugs SF 1242106 Shutdown bugs 1 Incorrect commit instead of rollback during shutdown 2 Crash or bugcheck during SuperServer shutdown with active attachments fixed by D Yemanov Not registered Crash occurred in service gfix code when it tried to reattach to a currently un available database Since a service cannot interact with the end user an endless loop leads to over flowing the service buffer and causing a crash as a result fixed by V Horsun DSQL Bugs SF 1408079 The parser was not validating string literal markers fixed by C Valderrama Not registered The engine would fail to parse the SQL ROLE keyword properly fixed by C Valderrama Not registered EXECUTE PROCEDURE did not check SQL permissions at the prepare stage fixed by D Yemanov SF 217042 Weird SQL constructions are not always properly validated 130 Bugs Fixed Partly fixed by C Valderrama SF 1108909 View could be created without rights on a table name like a b fixed by C Valderrama SF 512975 Clear embedded spaces and CR LF before DEFAULT clauses when storing them in system tables Implemented by C Valderrama SF 910423 Anomaly with ALTER TABLE altering a column s type to VARCHAR when de termining valid length of the string SQL gt CREATE TABLE tab i INTEGE
84. and brings some extra benefits It can be used in unions any kind of subquery and in UPDATE or DELETE statements It is available in both DSQL and PSQL Syntax Pattern SELECT szu ORDER BY lt expr_list gt ROWS lt exprl gt TO lt expr2 gt Examples 1 SELECT FROM T1 UNION ALL SELECT FROM T2 ORDER BY COL ROWS 10 TO 100 2 SELECT COL1 COL2 SELECT COL3 FROM T3 ORDER BY COL4 DESC ROWS 1 FROM T4 3 DELETE FROM T5 ORDER BY COL5 25 Data Manipulation Language DML ROWS 1 Points to Note 1 When lt expr2 gt is omitted then ROWS lt expr1 gt is semantically equivalent to FIRST lt expr1 gt When both lt expr1 gt and lt expr2 gt are used then ROWS expr1 TO expr2 means the same as FIRST lt expr2 gt expr1 1 SKIP lt expr1 gt 1 2 There is nothing that is semantically equivalent to a SKIP clause used without a FIRST clause Enhancements to UNION Handling The rules for UNION queries have been improved as follows UNION DISTINCT Keyword Implementation D Yemanov UNION DISTINCT is now allowed as a synonym for simple UNION in accordance with the SQL 99 specification It is a minor change DISTINCT is the default mode according to the standard Formerly Firebird did not support the explicit inclusion of the optional keyword DISTINCT Syntax Pattern UNION DISTINCT ALL Improved Typ
85. as no output parameters The semantics of a call is similar to an EXECUTE query the client has no cursor and execution continues until it reaches the end of the block or is terminated by a SUSPEND The client should preprocess only the head of the SQL statement or use instead of as the paramet er indicator because in the body of the block there may be references to local variables or arguments with a colon prefixed Example The user SQL is 22 Data Manipulation Language DML EX ECUTE BLOCK RETURNS LARE V INT Uu CQuungoo m p P IN NSERT INTO ELECT USPEND The preprocessed SQL is EXI A LH AS DECLARE V INTI CUTE BLOCK ETURNS BEGIN INSERT INTO SELECT SUSPEND END Derived Tables A Brinkman EGER TC EGER T FROM T INTO Y X INTEGER Y VARCHAR VALUES FROM T INTO Y X INTEGER Y VARCHAR VALUI X ES 53 Implemented support for derived tables in DSQL subqueries in FROM clause as defined by SQL200X A derived table is a set derived from a dynamic SELECT statement Derived tables can be nested if required to build complex queries and they can be involved in joins as though they were normal tables Syntax Patte or views rn SELECT se FROM table reference list lect list table reference list
86. atements RECREATE EXCEPTION and CREATE OR ALTER EXCEPTION feature re quest SF 1167973 have been implemented allowing either creating recreating or altering an excep tion depending on whether it already exists 18 Data Definition Language DDL RECREATE EXCEPTION RECREATE EXCEPTION is exactly like CREATE EXCEPTION if the exception does not already exist If it does exist its definition will be completely replaced if there are no dependencies on it CREATE OR ALTER EXCEPTION CREATE OR ALTER EXCEPTION will create the exception if it does not already exist or will alter the definition if it does without affecting dependencies ALTER EXTERNAL FUNCTION C Valderrama ALTER EXTERNAL FUNCTION has been implemented to enable the ent ry point or the mod ule name to be changed when the UDF declaration cannot be dropped due to existing dependencies COMMENT Statement Implemented C Valderrama The COMMENT statement has been implemented for setting metadata descriptions Syntax Pattern COMMENT ON DATABASE IS txt NULL COMMENT ON basic type name IS txt NULL COMMENT ON COLUMN tblviewname fieldname IS txt NULL COMMENT ON PARAMETER procname parname IS txt NULL An empty literal string will act as NULL since the internal code DYN in this case works this way with blobs basic type DOMAIN TABLE VIEW PROCEDURE TRIGGER EXTERNAL FUNCTION FILTER EXCEPTION ENERAT
87. ation for the tar gz install S opt firebird bin uninstall sh Solaris Install Firebird Classic amp SuperServer on Solaris 2 7 Sparc not currently available Please refer older releasenotes as a reference to 2 0 installations MacOS X Install Firebird Classic on MacOS X Darwin not currently available Please refer to older release notes as a reference to 2 0 installations FreeBSD Not currently available Please refer to older releasenotes as a reference to 2 0 installations Debian Not currently available Please refer to the relevant pages at the Debian site for your Debian version and Firebird 2 0 build 121 Chapter 17 Bugs Fixed The following bugs present in Firebird 1 5 were fixed Note that in many cases the bug fixes were backported to Firebird 1 5 x sub releases General Engine Bugs CORE 911 Leaving a Classic server process idle for a long period while a read only Read Committed transaction was active could cause segmentation faults A Vs fixed by V Horsun CORE 902 The server could crash intermittently during execution of DDL or DML statements fixed by V Horsun Not registered Assignments to columns deleted by a concurrent transaction were being improp erly allowed fixed by D Yemanov Not registered Error invalid transaction handle would be thrown when calling isc array lookup bounds from multiple threads fixed by D Yemanov Not registered Heavy concurrent load
88. ave been treated as diagnostic messages and as such were always sent to the console 83 Command line Utilities What the m2 command line switch does is to ensure that stats and plans information go to the same file the output has been redirected to Note Neither m nor m2 has an interactive counterpart through a SET command They are for use only as command line isql options r2 to Pass a Case Sensitive Role Name C Valderrama The sole objective of this parameter is to specify a case sensitive role name The default switch for this parameter is r Roles provided in the command line are uppercased With r2 the role is passed to the engine exactly as typed in the command line New Commands The following commands have been added or enhanced SET HEAD ing toggle C Valderrama Some people consider it useful to be able to do a SELECT inside isql and have the output sent to a file for additional processing later especially if the number of columns makes isql display impractic able However isql by default prints column headers and in this scenario they are a nuisance Therefore printing the column headers previously a fixed feature can now be enabled disabled interactively or from a script by means of the SET HEADing ON OFF command in the isql shell As is the case with other SET commands simply using SET HEAD will toggle the state between activated and deactivated Note
89. bel means interrupting the current most inner loop OLD Context Variables Now Read only D Yemanov The set of OLD context variables available in trigger modules is now read only An attempt to assign a value to OLD something will be rejected Note NEW context variables are now read only in AFTER triggers as well PSQL Stack Trace V Horsun The API client can now extract a simple stack trace Error Status Vector when an exception occurs during PSQL execution stored procedures or triggers A stack trace is represented by one string 2048 bytes max and consists of all the stored procedure and trigger names starting from the point where the exception occurred out to the outermost caller If the actual trace is longer than 2Kb it is truncated Additional items are appended to the status vector as follows isc_stack_trace isc_arg_string lt string length gt lt string gt isc_stack_trace is a new error code with value of 335544842L 51 Stored Procedure Language PSQL Examples Metadata creation CREATE TABLE ERR ID INT NOT NULL PRIMARY KEY NAME VARCHAR 16 CREATE EXCEPTION EX SET TERM CREATE OR ALTER PROCEDURE ERR 1 AS BEGIN EXCEPTION EX ID 3 END CREATE OR ALTER TRIGGER ERR BI FOR ERR BEFORE INSERT AS
90. case insensitive accent insensitive Czech language collation for WIN1250 char acter set Vietnamese Character Set Nguyen The Phuong A dos Santos Fernandes Charset WIN1258 for Vietnamese language Polish Collation Jaroslaw Glowacki A dos Santos Fernandes Added new collation ISO PLK for ISO8859 2 charset Polish language Character Set Bug Fixes A dos Santos Fernandes The following bugs related to character sets and collations were fixed 71 New Features for Text Data SF 1073212 An Order By on a big column with a COLLATE clause would terminate the server SF 939844 A query in a UNICODE database would throw a GDS Exception if it was longer than 263 characters SF 977785 Wrong character lengths were being returned from some multi byte character sets UTF 8 East Asian charsets SF 536243 A correct result is now returned when the UPPER function is applied to a UNI CODE_FSS string SF 942726 UPPER did not convert aacute to Aacute for ISO8859 1 SF 544630 Some problems were reported when connecting using UNICODE SF 540547 Some problems involving concatenation numeric fields and character set were fixed Unregistered bug A query could produce different results depending on the presence of an index when the last character of the string was the first character of a compression pair Unregistered bug SUBSTRING did not work correctly with a BLOB in a character set Unregistered bug Pattern matching with
91. changed 5 eie eie 94 Removed or Deprecated Parameters sssseeeeee ee eee 94 vi Firebird 2 0 Release Notes CreateInternal Window nocc ccccccccecececececeeeceeeeeceeeeeeeeeeeeeeeceeeseeeeeeeseeeeeeeees 94 DeadThreadsCollection is no longer used o cee cccecccecececececececececeteseseeeeeees 95 15 Known Compatibility Issues ettet ete eet bine eee Ets 96 The FIRBEBIRD Vari ble 5 E hee peoeoete tegere edet tede petente t egeo tn 96 Security in Firebird 2 All Platforms eese 96 SQL Migration ssuies D 97 DDL esses ida dees ole tise ates eret eterne eee eres A ete He eH iere eR ee PEE RR o sede 97 DME tenai a DENS HF ENS Id mex EN Ed 98 PSOE ete perse totes E A Gee ts dre ee P eedbere fea aee e CEPR REPRE ee cH beth 100 Configuration Parameters iiti bete teneret ie ken ehe Pre pebee Free ke N Ena 101 Command line Tools eee erede eere eee rrr erts 102 Change to gbak R Semantics sssseeee eene 102 Performance edere greco he CM Me 102 Isis Pu ERES 103 Windows Specifie Issues ether Eee eher eth EUR EE Rete noun 103 Windows Local Connection Protocol with XNet eee 103 Client Impersonation No Longer Works esseeee ee 103 Interactive Option Added to instsvc exe essee 104 16 INSTAELATION NOTES an eher et eene eese tote net aeo Rete Ree pae eto totae rep eene ai 105 Windows 32 bit Installs 5 eei eee
92. curity fdb firebird log 105 INSTALLATION NOTES firebird conf aliases conf Each model can be installed from a zipfile This method will be faster than the installer if you have plenty of experience installing Firebird from zipfiles It will be highly exasperating if you are a Firebird newbie It is assumed that 1 you understand how your network works 2 you understand why a client server system needs both a server and clients 3 you have read the rest of these release notes or at least realise that you need to read them if something seems to have gone wrong 4 you know to go to the firebird support list if you get stuck Join at http www yahoogroups com groups firebird support If you already have an earlier version of Firebird or InterBase on your server and you think you might want to go back to it set up your fall back position before you begin Use the existing version of GBAK to back up your database files in transportable format Go to your System directory and make backup copies of fbclient dll and or gds32 dll if you have applications that rely on finding those libraries there You might want to name the backup gds32 dll fb15 or gds32 dll fb103 or something similarly informative or hide it in another dir ectory It might be a good idea to make a backup of the Microsoft C runtime msvcp60 dll too The in staller shouldn t overwrite your version of this file but strange things have been known to hap
93. d maximum page cache size to 128K pages 2GB for 16K page size Faster Evaluation of IN and OR O Loa Constant IN predicate or multiple OR booleans are now evaluated faster 61 Optimizations Sparse bitmap operations were optimized to handle multiple OR booleans or an IN lt constant list gt predicate more efficiently improving performance of these operations Improved UNIQUE Retrieval A Brinkman The optimizer will now use a more realistic cost value for unique retrieval More Optimization of NOT Conditions D Yemanov NOT conditions are simplified and optimized via an index when possible Example NOT NOT A 0 gt A 0 NOT A gt 0 gt A lt 0 Distribute HAVING Conjunctions to the WHERE Clause If a HAVING clause or any outer level select refers to a field being grouped by this conjunct is dis tributed deeper in the execution path than the grouping thus allowing an index scan to be used In other words it allows the HAVING clause not only be treated as the WHERE clause in this case but also be optimized the same way Examples select rdb relation id count from rdb relations group by rdbS relation id having rdbS relation id gt 10 select from rdb relation id count from rdb relations group by rdbS relation id as grp id cnt where grp id 10 In both cases an index scan is performed instead of a full scan Distribute UNION Conjunctions to the Inner
94. derived table lt select expression Conclusions FOR UPDATE mode and row locking can only be performed for a final dataset they cannot be ap plied to a subquery Unions are allowed inside any subquery Clauses FIRST SKIP PLAN ORDER BY ROWS are allowed for any subquery Notes Either FIRST SKIP or ROWS is allowed but a syntax error is thrown if you try to mix the syn taxes An INSERT statement accepts a select expression to define a set to be inserted into a table Its SE 42 Data Manipulation Language DML LECT part supports all the features defined for select statments expressions UPDATE and DELETE statements are always based on an implicit cursor iterating through its tar get table and limited with the WHERE clause You may also specify the final parts of the select ex pression syntax to limit the number of affected rows or optimize the statement Clauses allowed at the end of UPDATE DELETE statements are PLAN ORDER BY and ROWS 43 Chapter 6 New Reserved Words and Changes The following keywords have been added or have changed status since Firebird 1 5 Those marked with an asterisk are not present in the SQL standard Newly Reserved Words BIT_LENGTH BOTH CHAR_LENGTH CHARACTER_LENGTH CLOSE CROSS FETCH LEADING LOWER OCTET_LENGTH OPEN ROWS TRAILING TRIM Changed from Non reserved to Reserved USING Keywords Added as Non reserved BACKUP BLOC
95. doc sql extensions README set transaction txt SHOW DATABASE now Returns ODS Version Number C Valderrama ODS On Disk Structure version is now returned in the SHOW DATABASE command C Valder rama Ability to show the line number where an error happened in a script C Valderrama In previous versions the only reasonable way to know where a script had caused an error was using the switch e for echoing commands o to send the output to a file and m to merge the error output to the same file This way you could observe the commands isql executed and the errors if they exist The script continued executing to the end The server only gives a line number related to the single command statement that it s executing for some DSQL failures For other errors you only know the statement caused problems With the addition of b for bail as described in 1 the user is given the power to tell isql to stop ex 85 Command line Utilities ecuting scripts when an error happens but you still need to echo the commands to the output file to discover which statement caused the failure Now the ability to signal the script related line number of a failure enables the user to go to the script directly and find the offending statement When the server provides line and column information you will be told the exact line of DML in the script that caused the problem When the server only indic ates a failure you will be told the starting
96. e 2 The NOT DISTINCT predicate can be optimized using an index if one is available NULL Comparison Rule Relaxed D Yemanov A NULL literal can now be treated as a value in all expressions without returning a syntax error You may now specify expressions such as NULL NULL NULL NULL UJ o UU p tV Note All such expressions evaluate to NULL The change does not alter nullability aware semantics of the engine it simply relaxes the syntax restrictions a little NULLs Ordering Changed to Comply with Standard N Samofatov Placement of nulls in an ordered set has been changed to accord with the SOL standard that null or dering be consistent i e if ASC ENDING order puts them at the bottom then DESC ENDING puts them at the top or vice versa This applies only to databases created under the new on disk structure since it needs to use the index changes in order to work Examples Database proc fdb SOL create table gnull a int SOL insert into gnull values null SQL gt insert into gnull values 1 SOL select a from gnull order by a A null 1 SOL select a from gnull order by a asc A 29 Data Manipulation Language DML null a SQL gt select a from A 1 null SOL select a from A null 1 SOL select a from A 1 null SOL select a f
97. e Now it will be ne cessary to adjust your view trigger code in order to make the update happen at all New Reserved Words Keywords A number of new reserved keywords are introduced The full list is available in the chapter New Reserved Words and Changes and also in Firebirds CVS tree in doc sql extentions SREADME keywords You must ensure that your DSQL statements and proced ure trigger sources do not contain those keywords as identifiers Note In a Dialect 3 database such identifiers can be redefined using the same words as long as the identifiers are enclosed in double quotes In a Dialect 1 database there is no way to retain them they must be redefined with new legal words CHECK Constraint Change Formerly CHECK constraints were not SQL standard compliant in regard to the handling of NULL For example CHECK DEPTNO IN 10 20 30 should allow NULL in the DEPTNO column but it did not In Firebird 2 0 if you need to make NULL invalid in a CHECK constraint you must do so expli citly by extending the constraint Using the example above CHECK DEPTNO IN 10 20 30 AND DEPTNO IS NOT NULL DML Changed Ambiguity Rules in SQL A Brinkman In summary the changes are 1 When an alias is present for a table that alias and not the table identifier must be used to qualify columns or no alias is used Use of an alias makes it invalid to use the table identifier to qualify a column
98. e Coercion in UNIONs A Brinkman Automatic type coercion logic between subsets of a union is now more intelligent Resolution of the data type of the result of an aggregation over values of compatible data types such as case expres sions and columns at the same position in a union query expression now uses smarter rules Syntax Rules Let DTS be the set of data types over which we must determine the final result data type 1 All of the data types in DTS shall be comparable 2 Case a If any of the data types in DTS is character string then i If any of the data types in DTS is variable length character string then the result data type is variable length character string with maximum length in characters equal to the largest maximum amongst the data types in DTS ii Otherwise the result data type is fixed length character string with length in characters equal to the maximum of the lengths in characters of the data types in DTS ii The characterset collation is used from the first character string data type in DTS 26 Data Manipulation Language DML b Ifall of the data types in DTS are exact numeric then the result data type is exact numeric with scale equal to the maximum of the scales of the data types in DTS and the maximum precision of all data types in DTS Note NOTE Checking for precision overflows is done at run time only The developer should take measures to avoid the aggregation resolving to a precisi
99. e client is to use to read strings If no cli ent or connection character set is specified character set NONE is assumed Two special character sets NONE and OCTETS can be used in declarations However OCTETS cannot be used as a connection character set The two sets are similar except that the space character of NONE is ASCII 0x20 whereas the space character OCTETS is 0x00 NONE and OCTETS are special in the sense that they do not follow the rule that other charsets do regarding conversions e With other character sets conversion is performed as CHARSET1 gt UNICODE gt CHARSET2 With NONE OCTETS the bytes are just copied NONE OCTETS gt CHARSET2 and CHAR SET1 gt NONE OCTETS Enhancements Enhancements include Well formedness checks Some character sets especially multi byte do not accept just any string Now the engine verifies that strings are well formed when assigning from NONE OCTETS and when strings sent by the client the statement string and parameters Uppercasing In FB 1 5 X only ASCII characters are uppercased in a character set s default binary collation order which is used if no collation is specified For example isgl q ch dos850 SOL create database test fdb SQL create table t c char 1 character set dos850 SQL gt insert into t values a SQL gt insert into t values e SOL insert into t values SOL insert into t values 66 New
100. eate database localhost test fdb SQL gt quit If the DatabaseAccess value in opt firebird firebird conf is set to Full or a restricted path value for example Database Access var firebird another alternative to step 2 is to create the physical database file directly using the absolute path with the filename opt firebird bin isgl u sysdba p password SOL create database var firebird test fdb SQL quit If you use this configuration the database file can also be directly accessed without an entry in the aliases file opt firebird bin isgl u sysdba p password SOL connect var firebird test fdb SQL gt quit 119 INSTALLATION NOTES Utility Scripts In addition to the standard install files the following scripts are provided in the bin directory of this re lease changeDBAPassword sh Change the Firebird SYSDBA user password For Superserver this script will change the init script etc rc d init d firebird to use the new password as well createAliasDB sh Usage createAliasDB sh lt dbname gt lt dbpath gt This script creates a new physical database and adds an entry in the aliases conf file fb config A script that can be used in makefiles to generate the required include paths and lib include direct ives for the installed version of Firebird b config help will give a complete list of options changeGdsLibraryCompatibleLink sh Classic only Change the client
101. ecified sorts in UNICODE code point order The UNICODE collation sorts using UCA Unicode Collation Algorithm Sort order sample isgl q ch dos850 SQL gt create database test fdb SQL create table t c char 1 character set utf8 SQL gt insert into t values SOL insert into t values SOL insert into t values SOL insert into t values SOL insert into t values SOL select from t order by CE cock CE CE ct collate ucs basic Brazilian collations Two case insensitive accent insensitive collations were created for Brazil WIN PTBR for WIN1252 and PT BR for ISO8859 1 Sort order and equality sample isgl q ch dos850 SOL create database test fdb SQL gt create table t c char 1 character set iso8859 1 collate pt br SOL insert into t values SQL gt insert into t values SOL insert into t values SQL gt insert into t values SOL select PESE DC TT t 69 New Features for Text Data SQL gt select from t where c Drivers New character sets and collations are implemented through dynamic libraries and installed in the serv er with a manifest file in the intl subdirectory For an example see fbintl conf Not all implemented character sets and collations need to be listed in the manifest file Only those lis ted are available and duplications are not loaded Adding More Character Sets to a Database For installing additional charact
102. ected to provide full support for SQL 99 sequence generators which allows the required increment values to be specified at the DDL level Un less there is a vital need to use a step value that is not 1 use of a NEXT VALUE FOR value expression instead of the GEN_ID function is recommended 2 GEN_ID lt name gt 0 allows you to retrieve the current sequence value but it should never be used in insert update statements as it produces a high risk of uniqueness violations in a concur rent environment RETURNING Clause for Insert Statements D Yemanov The RETURNING clause syntax has been implemented for the INSERT statement enabling the re turn of a result set from the INSERT statement The set contains the column values actually stored Most common usage would be for retrieving the value of the primary key generated inside a BE FORE trigger Available in DSQL and PSQL Syntax Pattern INSERT INTO VALUES RETURNING column list INTO variable list Example s 1 INSERT INTO T1 F1 F2 VALUES Fl F2 RETURNING Fl F2 INTO V1 V2 INSERT INTO T2 F1 F2 VALUES 1 2 RETURNING ID INTO PK 39 Data Manipulation Language DML Note 1 The INTO part i e the variable list is allowed in PSQL only to assign local variables and re jected in DSQL 2 In DSQL values are being returned within the same protocol roundtrip as the INSERT itself is executed
103. ed client will still do the trick of course Change to WNET NetBEUI Protocol WNET a k a NetBEUI protocol no longer performs client impersonation In all previous Firebird versions remote requests via WNET are performed in the context of the client security token Since the server serves every connection according to its client security credentials this means that if the client machine is running some OS user from an NT domain that user should have appropriate permissions to access the physical database file UDF libraries etc on the server filesystem This situation is contrary to what is generally regarded as proper for a client server setup with a protected database Such impersonation has been removed in Firebird 2 0 WNET connections are now truly client server and behave the same way as TCP ones i e with no presumptions with regard to the rights of OS users Reworking of Garbage Collection V Horsun Since Firebird 1 0 and earlier the Superserver engine has performed background garbage collection maintaining information about each new record version produced by an UPDATE or DELETE state ment As soon as the old versions are no longer interesting i e when they become older than the Oldest Snapshot transaction seen in the gstat header output the engine signals for them to be re moved by the garbage collector Background GC eliminates the need to re read the pages containing these versions via a S
104. ed value is the same as would be returned by the CURRENT CONNECTION pseudo variable 33 Data Manipulation Language DML CURRENT_USER The current user The returned value is the same as would be returned by the CURRENT USER pseudo variable or the predefined variable USER CURRENT ROLE Current role for the connection Returns the same value as the CUR RENT ROLE pseudo variable Notes To avoid DoS attacks against the Firebird Server the number of variables stored for each transaction or session context is limited to 1000 Example of Use set creat cCerm Fr te procedure set context User ID varchar 40 Trn ID integer as begin RDBSSET CONTEXT USER TRANSACTION Trn ID Trn ID RDBSSET CONTEXT USER TRANSACTION User ID User ID end create table journal jrn id integer not null primary key jrn las jrn las jrn las tuser varchar 40 taddr varchar 255 ttransaction integer CREATE TRIGGER UI JOURNAL FOR JOURNAL AFTER INSERT OR UPDATE as begin new jrn lastuser rdb get context USER TRANSACTION User ID new jrn lastaddr rdb get context SYSTEM CLIENT ADDRESS new jrn lasttransaction rdb get context USER TRANSACTION Trn ID end commit xecute procedure set context skidder 1 insert into journal jrn id values 0 set term Since rdb set context returns 1 o
105. egistered Incorrect accounting of attachment pointers used inside the lock structure was causing the server to crash fixed by N Samofatov Not registered In v 1 5 random crashes would occur during a restore fixed by J Starkey Not registered Crash lock up with multiple calls of isc_dsql_prepare for a single statement fixed by N Samofatov Not registered Server would crash when the system year was set too high or too low fixed by D Yemanov Not registered Server would crash when the stream number exceeded the limit fixed by D Yemanov Not registered Server would crash when outer aggregation was performed and explicit plans were used in subqueries fixed by D Yemanov 135 Bugs Fixed Not registered DECLARE FILTER would cause the server to crash fixed by A Peshkov Not registered The server would crash when a PLAN for a VIEW was specified but no table ali as was given fixed by V Horsun Not registered Server would crash during the table metadata scan in some cases fixed by D Yemanov Not registered Server would crash when too big a key was specified for an index retrieval fixed by D Yemanov Not registered Server would crash when manipulating input DPB due to memory corruption in Parameter Blocks management fixed by C Valderrama Not registered Server would crash when attempting to restore a database backup with corrupted VARCHAR data fixed by D Yemanov Remote Interface Bugs Not registered A
106. ent or actually client defined Firebird 2 Server side Hashing To be able to use stronger hashes another approach was called for The hash to be stored on the server should always be calculated on the server side Such a schema already exists in Firebird in the Ser vices API This led to the decision to use the Services API for any client activity related to user man agement Now gsec and the isc_user_add modify delete API functions all use services to access the security database Embedded access to Classic server on POSIX is the exception see below It became quite easy to make any changes to the way passwords are hashed it is always performed by the server It is no longer gsec s problem to calculate the hash for the security database it simply asks services to do the work It is worth noting that the new gsec works successfully with older Firebird versions as long as the server s architecture supports services The SHA 1 Hashing Algorithm This method leads to the situation where 1 a hash valid for user A is invalid for user B 2 when a user changes his password even to exactly the same string as before the data stored in RDB USERS RDB PASSWD is new Although this situation does not increase resistance to a brute force attempt to crack the password it does make visual analysis of a stolen password database much harder The New Security Database The structure of security database was changed In general
107. eout counting 3 database lock was not being released after bringing database online in the exclusive mode 4 removed a5 sec timeout when bringing database online in the shared mode fixed by D Yemanov SF 1186607 Foreign key relation VARCHAR lt gt INT should not have caused an exception fixed by V Horsun SF 1211325 Fixed problems with BLOBs in external tables fixed by V Horsun Not registered After an attempt to create view v cl as select 1 from v all clones of the system request would remain active forever fixed by A Peshkov SF 1191006 Use of WHERE params in SUM would return incorrect results fixed by A Brinkman SF 750662 Fixed a bug involving multiple declaration of blob filters fixed by D Yemanov SF 743679 FIRST SKIP was not as well implemented as it could be fixed by D Yemanov Not registered CPU load would rise to 100 when an I O error caused a rollover to a non existent shadow fixed by D Yemanov 126 Bugs Fixed Not registered Cannot find record fragment bugcheck could occur during garbage collection on the system tables fixed by V Horsun SF 1211328 Error reporting cited maximum BLOB size wrongly fixed by D Yemanov SF 1292007 Duplicated field names in INSERT and UPDATE statements were getting through fixed by C Valderrama Not registered The SQL string was being stored truncated within the RDB _SOURCE columns in some cases fixed by D Yemanov Not registered Broke
108. er 6 and 7 are reserved for future use Jump nodes A jump node is a reference to a node somewhere in the page It contains offset information about the specific node and the prefix data from the referenced node but prefix compression is also done on the jump nodes themselves Ideally a new jump node is generated after the first node that is found after every jumpAreaSize but that s only the case on deactivate active an index or inserting nodes in the same order as they will be stored in the index If nodes are inserted between two jump node references only the offsets are updated but only if the offsets don t exceed a specific threshold 10 96 When a node is deleted only offsets are updated or a jump node is removed This means a little hole can exist between the last jump node and the first node so we don t waste time on generating new jump nodes The prefix and length are also stored by variable length encoding Figure 8 3 Example data x size in x bytes Pointer after fixed header 0x22 Pointer after jump info 0x29 Pointer to first jump node 0x29 6 jump node 1 5 Gump node 2 0x34 Jump node 1 is referencing to the node that represents FIREBIRD as data because this node has a prefix of 2 the first 2 characters FI are stored also on the jump node 58 Enhancements to Indexing Our next jump node points to a node that represents FUEL with also a prefix of 2 Thus jump node 2 should contain FU b
109. er sets and collations into a database the character sets and collations should be registered in the database s system tables rdb character sets and rdb collations The file misc intl sql in your Firebird 2 installation is a script of stored procedures for registering and unre gistering them New Character Sets and Collations Implemented ES ES CI Al for ISO8859 1 Character Set A dos Santos Fernandes Spanish language case and accent insensitive collation for ISO8859 1 character set KOI8 R O Loa A Karyakin Russian language character set and dictionary collation KOI8 U O Loa A Karyakin Ukrainian language character set and dictionary collation WIN1257_LV O Loa A Karyakin Latvian dictionary collation WIN1257_LT 70 New Features for Text Data O Loa A Karyakin Lithuanian dictionary collation WIN1257_EE O Loa A Karyakin Estonian dictionary collation UTF8 A dos Santos Fernandes Unicode 4 0 support with UTF8 character set and collations UCS BASIC and UNICODE Brazilian collations A dos Santos Fernandes P H Albanez 1 Collation PT BR for ISO8859 character set 2 Collation WIN PTBR for WIN1252 character set Bosnian Collation F Hasovic New Bosnian language collation BS BA was added for WIN1250 character set Czech Collations I Prenosil A dos Santos Fernandes WIN CZ case insensitive Czech language collation for WIN1250 character set e WIN CZ CI AE
110. ere a procedure could not be dropped fixed by V Horsun SF 1238104 Internal sweep report was incorrect fixed by C Valderrama SF 1371274 The infamous Datatype unknown error when attempting some castings has been eliminated It is now possible to use CAST to advise the engine about the data type of a parameter fixed by D Yemanov SF 1292106 ORDER BY with FOR UPDATE WITH LOCK would trash the index fixed by D Yemanov SF 1368741 UPPER was returning wrong results 132 Bugs Fixed fixed by A dos Santos Fernandes PSQL Bugs CORE 921 A bug in EXECUTE STATEMENT implementation could cause a core dump dur ing PSQL execution fixed by A Peshkov SF 1422471 A memory leak was exhibited in EXECUTE STATEMENT fixed by A Peshkov Not registered ROW_COUNT was getting cleared after SUSPEND execution fixed by D Yemanov SF 1124720 Problem with FOR EXECUTE STATEMENT DO SUSPEND fixed by A Peshkov Not registered Memory leakage was occurring when selectable stored procedures were called from PSQL or in subqueries fixed by N Samofatov Not registered The wrong error would be reported when non active contexts were accessed in multi action triggers fixed by D Yemanov Not registered An internal error was reported when attempting to pass return blobs to from string functions inside PSQL fixed by D Yemanov 133 Bugs Fixed Crash Conditions Not registered A crash could occur if some bad
111. errors could also show up during the restore process when you are migrating databases to the new version It will be necessary to correct these conditions in original database before you attempt to perform a backup restore cycle Plan must refer to all tables in query Using a plan without a reference to all tables in query is now illegal and will cause an exception Some previous versions would accept plans with missing references but it was a bug PSQL Restrictions on assignment to context variables in triggers Assignments to the OLD context variables are now prohibited for every kind of trigger Assignments to NEW context variables in AFTER triggers are also prohibited 100 Known Compatibility Issues Tip If you get an unexpected error Cannot update a read only column then violation of one of these restrictions will be the source of the exception Reference to current of lt cursor gt outside scope of loop In Firebird 1 5 and earlier referring to current of lt cursor gt outside the scope of the cursor loop was accepted by the PSQL parser allowing the likelihood of run time occurring as a result Now it will be rejected in the procedure or trigger definition NULLS are now lowest for sorts NULL is now treated as the lowest possible value for ordering purposes and sets ordered on nul lable criteria are sorted accordingly Thus for ascending sorts NULLs are placed at the begi
112. es are still checked and enforced Users that are assigned privileges in a Firebird data base are not dependent on the existence of the user in the security database Compatibility You may run any number of applications with the embedded server without any conflicts Having a full Firebird or InterBase server running on the same machine is not a problem either However be aware that you cannot access a single database from a number of embedded servers sim ultaneously regardless of whether they be embedded or full servers An embedded server has the Su perServer architecture and hence exclusively locks attached databases Installing an Embedded Server Application Application Root Just copy fbembed dll icudt30 dll icuin30 dll and icuuc30 dll into the directory with your applic ation exectable You should also copy firebird msg and firebird conf if necessary to the same directory Note You will need firebird conf only if it is necessary to set some non default configuration para meter for the embedded server If external libraries are required for your application such as INTL support fbintl dll and fbintl conf or UDF libraries create subdirectories beneath the application root for them emulat ing the Firebird server ones e g intl or udf respectively Rename fbembed dll Rename fbembed dll to either fbclient dll or gds32 dll according to which is required by your database connectivity software
113. f set Firebird version 2 efficiently cleans up dead threads straight away 101 Known Compatibility Issues Command line Tools Change to gbak R Semantics An important change has been done to prevent accidental database overwrites as the result of users mistakenly treating R as an abbreviation for restore gbak R was formerly a shortcut for REPLACE DATABASE Now the R switch no longer restores a database by overwriting an ex isting one but instead reports an error If you actually want the former behaviour you have two alternatives Specify the full syntax gbak REPLACE_DATABASE There is a new shortcut for the REPLACE_DATABASE switch goak REP OR Use the new command R ECREATE DATABASE OVERWRITE The R shortcut now represents the R ECREATE DATABASE switch and the OVERWRITE keyword must be present in either the full or the abbreviated form Warning If you use the full syntax you are expected to know what this restore mode actually means and have some recovery strategy available if the backup subsequently turns out to be unrestorable Performance The following changes should be noted as possible sources of performance loss ALL predicate may be slow Formerly using the ALL existence predicate could return wrong results in cases where an index was involved To correct the bug this version will never use an index with ALL This change may degrade performance S
114. ff by default Caution If you are considering enabling multi hop capability please study the Warning text in the chapter on Security and in the documentation for this parameter in the firebird conf file 93 New Configuration Parameters and Changes GCPolicy V Horsun Garbage collection policy It is now possible to choose the policy for garbage collection on Super Server The possible settings are cooperative background and combined as explained in the notes for GPolicy in firebird conf Not applicable to Classic which supports only cooperative garbage collection New parameter OldColumnNaming P Reeves The parameter OldColumnNaming has been ported forward from Firebird 1 5 3 This parameter al lows users to revert to pre V1 5 column naming behaviour in SELECT expressions The installation default is O disabled If it is enabled the engine will not attempt to supply run time identifiers e g CONCATENATION for derived fields where the developer has neglected to provide identifiers Important This setting affects all databases on the server and will potentially produce exceptions or unpre dicted results where mixed applications are implemented UsePriorityScheduler A Peshkov Setting this parameter to zero now disables switching of thread priorities completely It affects only the Win32 SuperServer TCPNoNagle has changed K Kuznetzov The default value for TcpNoNagle is now TC
115. forma tion about the current connection and current transaction They also provide a mechanism to retrieve user context data and associate it with the transaction or connection Syntax Pattern RDBSSET CONTEXT namespace variable value RDBSGET CONTEXT namespace variable These functions are really a form of external function that exists inside the database intead of being called from a dynamically loaded library The following declarations are made automatically by the engine at database creation time Declaration DECLARE EXTERNAL FUNCTION RDBS GET CONTEXT VARCHAR 80 VARCHAR 80 RETURNS VARCHAR 255 FREE IT DECLARE EXTERNAL FUNCTION RDBSSET CONTEXT VARCHAR 80 VARCHAR 80 VARCHAR 255 RETURNS INTEGER BY VALUE 32 Data Manipulation Language DML Usage RDB SET_CONTEXT and RDB GET_CONTEXT set and retrieve the current value of a context variable Groups of context variables with similar properties are identified by Namespace identifiers The namespace determines the usage rules such as whether the variables may be read and written to and by whom Note Namespace and variable names are case sensitive e RDBS GET CONTEXT retrieves current value of a variable If the variable does not exist in namespace the function returns NULL RDBSSET CONTEXT sets a value for specific variable if it is writable The functi
116. ggers passed the DML operation to the un derlying table and executed the triggers as well The result was that if you followed the official documentation and used triggers to perform a table update inserted to updated or deleted from the underlying table the operation was done twice once executing the view s trigger code and again executing the table s trigger code This situation caused performance problems or excep tions particularly if blobs were involved Now if you define triggers for a naturally updatable view it becomes effectively like a non updatable view that has triggers to make it updatable in that a DML request has to be defined on the view to make the operation on the underlying table happen viz 1 if the view s triggers define a DML operation on the underlying table the operation in ques tion is executed once and the table triggers will operate on the outcome of the view s triggers 2 if the view s triggers do not define any DML request on the underlying table then no DML operation will take place in that table 97 Known Compatibility Issues Important Some existing code may depend on the assumption that requesting a DML operation on an up datable view with triggers defined would cause the said operation to occur automatically as it does for an updatable view with no triggers For example this feature might have been used as a quick way to write records to a log table en route to the real updat
117. gment basis This means that for a compound index on columns A B C three selectivity values will be calculated reflecting a full index match as well as all partial matches That is to say the selectivity of the multi segment index involves those of segment A alone as it would be if it were a single segment index segments A and B combined as it would be if it were a double segment index and the full three segment match A B C i e all the ways a compound index can be used This opens more opportunities to the optimizer for clever access path decisions in cases involving par tial index matches The per segment selectivity values are stored in the column RDB STATISTICS of table 55 Enhancements to Indexing RDB INDEX_SEGMENTS The column of the same name in RDB INDICES is kept for compatibil ity and still represents the total index selectivity that is used for a full index match Firebird Index Structure from ODS11 Onward Abvisie 2005 Arno Brinkman The aims achieved by the new structure were better support for deleting an index key out of many duplicates caused slow garbage collection support for bigger record numbers than 32 bits 40 bits to increase index key size 1 4 page size Figure 8 1 Existing structure ODS10 and lower header typedef struct btr struct pag btr_header SLONG btr_sibling vight sibling page SLONG btr_left_sibling left sibling page SLO
118. he local IPC protocol as it used a windows message to connect the server In v 2 0 it is no longer necessary and the server itself does not need this option However some custom UDFs may use the Win32 messaging facilities and this option allows them to work as expected Note instsvc exe is a command line utility for installing and uninstalling the Firebird service It does not apply to Windows systems that do not have the ability to run services Win9x WinME For detailed usage instructions refer to the document README instsvc in the doc directory of your Firebird installation 104 Chapter 16 INSTALLATION NOTES Please read the previous chapter Known Compatibility Issues before you set out to install Firebird 2 0 Windows 32 bit Installs READ THIS FIRST On Windows you have three server models to choose from Superserver Classic and Embedded Server This means you have some decisions to make before installing Firebird 2 0 Make sure you are logged in as Administrator doesn t apply on Win9x or ME Check to make sure that there is no FIREBIRD environment variable defined that is visible to Ad ministrator level users or to the LocalSystem user see the section called The FIREBIRD Vari able at the start of the previous chapter The Superserver and Classic models as well as server tools only and client only can be installed using the Windows installer application For a full relea
119. ined we lose in performance If some variant is wrongly treated as in variant we see wrong results Example select from rdbSrelations where rdbSrelation_id lt select rdb relation id from rdb database This query performs only one fetch from rdb database instead of evaluating the subquery for every row of rdb relations ROLLBACK RETAIN Syntax Support D Yemanov Firebird 2 0 adds an optional RETAIN clause to the DSQL ROLLBACK statement to make it consistent with COMMIT RETAIN See ROLLBACK RETAIN Syntax in the chapter about DML No More Registry Search on Win32 Servers D Yemanov The root directory lookup path has changed so that server processes on Windows no longer use the Registry Important The command line utilities still check the Registry More Optimizer Improvements A Brinkman Better cost based calculation has been included in the optimizer routines 10 New in Firebird 2 0 ODS Changes Various Contributors The new On Disk Structure ODS is ODS11 For more information see the chapter ODS Changes 11 Chapter 3 Changes to the Firebird API and ODS API Application Programming Interface Some needed changes have been performed in the Firebird API They include Cleanup of ibase h D Yemanov A Peshkov The API header file ibase h has been subjected to a cleanup with the result that public headers no longer contain private declarations Loc
120. ing a name for a user defined blob subtype remember to commit after the insertion SQL gt insert into rdb types CON values RDBSFIELD SUB TYPE 100 XDR test type 0 SOL commit SQL gt declare filter pesh2 input type xdr output type text CON entry point p2 module name p SOL show filter pesh2 BLOB Filter PESH2 Input subtype 100 Output subtype 1 Filter library is p Entry point is p2 21 Data Manipulation Language DML New and Extended DSQL Syntaxes In this section are details of DML language statements or constructs that have been added to the DSQL language set in Firebird 2 0 EXECUTE BLOCK Statement V Horsun The SQL language extension EXECUTE BLOCK makes dynamic PSQL available to SELECT spe cifications It has the effect of allowing a self contained block of PSQL code to be executed in dy namic SQL as if it were a stored procedure Syntax pattern EXECUTE BLOCK param datatype param datatype RETURNS param datatype param datatype AS DECLARE VARIABLE var datatype BEGIN END For the client the call isc_dsql_sql_info with the parameter isc_info_sql_stmt_type re turns isc info sql stmt select if the block has output parameters The semantics of a call is similar to a SELECT query the client has a cursor open can fetch data from it and must close it after use e isc info sql stmt exec procedure if the block h
121. is limited to some subtree path depending on a predicate If any search criterion is used on other columns which are indexed then a range index scan is per formed in advance and every fetched key has its row id validated against the resulting bitmap Then a data page is read and the required row is fetched Note Note that a navigational scan incurs random page I O as reads are not optimized A sort operation performs an external sort of the given stream retrieval A join can be performed either via the nested loops algorithm JOIN plan or via the sort merge al gorithm MERGE plan e An inner nested loop join may contain as many streams as are required to be joined All of them are equivalent Anouter nested loops join always operates with two streams so you ll see nested JOIN clauses in the case of 3 or more outer streams joined A sort merge operates with two input streams which are sorted beforehand then merged in a single run Examples LECT RD B OM RDBSR ERE RDBSRELATION NAME LIKE RDBS ELATIONS NATURAL R H R LAN RDBSRE RDER BY RDBSRELATION NAME 1 Ur RELATION NAME LATIONS O uz u UJ ELECT R RDBSRELATION NAME RF RDBSFIELD NAM ROM RDBSRELATIONS R JOIN RDBSRELATION FIELDS RF ON R RDBSRELATION NAME RF RDBSRELATION NAME PLAN MERGE SORT R NATURAL SORT RF NATURAL Lr n ca
122. ist the installer will prompt you and create it if it doesn t exist Here you can also opt not to have the installer create Startup Menu icons by checking off the op tion If you are installing on Windows 9x or WinMe or you plan to run the server as an applica tion in another Win32 environment keep the icons option checked on Next you should see a screen where you choose the installation you want e Setup Firebird Database Server 2 0 E ioj xl Select Components By Which components should be installed Select the components you want to install clear the components you do not want to install Click Next when you are ready to continue Custom installation Server components amp Classic Server binary 1 8 MB Q Super Server binary 2 0 MB Developer and admin tools components 6 8 MB Client components 2 2 MB Current selection requires at least 14 3 MB of disk space lt Back Cancel English Choose the installation you want and hit the Next button to carry on responding to dialogs 109 INSTALLATION NOTES Note If you re installing a server you should choose Superserver preselected by the installer or Classic as seen in the image above Leave Server components and Developer and admin tools compon ents checked on For a client only install check off Server components leaving Client components and option ally Developer and admin tools components
123. it becomes a maintenance nightmare you can create a role assign a package of rights to that role and then grant the role to one or more users Any change to the role s rights affect all those users By using WITH ADMIN OPTION the grantor typically the role creator gives the grantee the right to become a grantor of the same role in turn Until FB v2 this ability couldn t be removed unless the original grantor fiddled with system tables directly Now the ability to grant the role can be removed by the original grantor with REVOKE ADMIN OPTION FROM user SET DROP DEFAULT Clauses for ALTER TABLE C Valderrama Domains allow their defaults to be changed or dropped It seems natural that table fields can be ma nipulated the same way without going directly to the system tables Syntax Pattern ALTER TABLE t ALTER COLUMN c SET DEFAULT default value ALTER TABLE t ALTER COLUMN c DROP DEFAULT Note Array fields cannot have a default value If you change the type of a field the default may remain in place This is because a field can be given the type of a domain with a default but the field itself can override such domain On the other hand the field can be given a type directly in whose case the default belongs logically to the field albeit the information is kept on an implicit domain created behind scenes New Syntaxes for Changing Exceptions D Yemanov The DDL st
124. k Timeout for WAIT Transactions A Karyakin D Yemanov The new feature extends the WAIT mode by making provision to set a finite time interval to wait for the concurrent transactions If the timeout has passed an error isc_lock_timeout is reported Timeout intervals can now be specified per transaction using the new TPB constant isc_tpb_lock_timeout in the API Note The DSQL equivalent is implemented via the LOCK TIMEOUT lt value gt clause of the SET TRANSACTION statement isc dsql sql info Now Includes Relation Aliases D Yemanov The function call isc dsql sql info has been extended to enable relation aliases to be retrieved if re quired Enhancement to isc blob lookup desc A dos Santos Fernandes isc blob lookup desc now also describes blobs that are outputs of stored procedures 12 Changes to the Firebird API and ODS API Identifies Client Version N Samofatov The macro definition FB API VER is added to ibase h to indicate the current API version The num ber corresponds to the appropriate Firebird version The current value of FB_API_VER is 20 two digit equivalent of 2 0 This macro can be used by cli ent applications to check the version of ibase h its being compiled with Additions to the isc_database_info Structure V Horsun The following items have been added to the isc_database_info function call structure isc_info_active_tran_count Returns the number of current
125. l walk 63 Chapter 10 New Features for Text Data New String Functions Two new string functions were added LOWER A dos Santos Fernandes LOWER returns the input argument converted to all lower case characters Example isql q ch dos850 SOL create database test fdb SOL create table c char 1 character set dos850 SOL insert into t values A SOL insert into values E SQL insert into values SQL insert into values SOL C LOWER CGrocE ct ct Emp m Q9 0o TRIM A dos Santos Fernandes TRIM trims characters default blanks from the left and or right of a string Syntax Pattern TRIM left paren trim specification trim character FROM value expression right paren trim specification LEADING TRAILING BOTH lt trim character gt lt value expression gt Rules 64 New Features for Text Data 1 If lt trim specification is not specified BOTH is assumed 2 If lt trim character is not specified is assumed 3 If lt trim specification and or trim character is specified FROM should be specified 4 If trim specification and trim character is not specified FROM should not be specified Examples A select rdb relation name trim leading RDBS from rdb relation name from rdbSrelations where rdbS relation name starting with RDBS B select trim
126. lans PLAN stream retrieval sorted streams joined streams stream retrieval natural scan indexed retrieval navigational scan natural scan stream alias NATURAL indexed retrieval stream alias INDEX index name index name navigational scan stream alias ORDER index name INDEX index name index name sorted streams SORT stream retrieval joined streams JOIN stream retrieval stream retrieval stream retrieval 35 Data Manipulation Language DML SORT MERGE lt sorted_streams gt lt sorted_streams gt Details Natural scan means that all rows are fetched in their natural storage order Thus all pages must be read before search criteria are validated Indexed retrieval uses an index range scan to find row ids that match the given search criteria The found matches are combined in a sparse bitmap which is sorted by page numbers so every data page will be read only once After that the table pages are read and required rows are fetched from them Navigational scan uses an index to return rows in the given order if such an operation is appropriate The index b tree is walked from the leftmost node to the rightmost one If any search criterion is used on a column specified in an ORDER BY clause the navigation
127. les 46 Stored Procedure Language PSQL iw al Q ARE RNAME CHAR 31 ARE C CURSOR FOR SELECT RDBSRELATION_NAM FROM RDBSRELATIONS Oo E E a I LH IN PEN C HILE 1 1 DO EGIN FETCH C INTO RNAME IF ROW COUNT 0 THEN LEAVE SUSPEND END CLOSE C ND Ej ECLARE RNAME CHAR 31 ARE FNAME CHAR 31 ECLARE C CURSOR FOR OUU Lt Q SELECT RDBSFIELD_NAME FROM RDB RELATION_FIELDS WHERE RDB RELATION_NAME RNAM ORDER BY RDBSFIELD POSITION LH BEGIN FOR SELECT RDBSRELATION NAM FROM RDBSRELATIONS INTO RNAME LH INTO FNAME CI Z a J 47 Stored Procedure Language PSQL Note Cursor declaration is allowed only in the declaration section of a PSQL block procedure trigger as with any regular local variable declaration Cursor names are required to be unique in the given context They must not conflict with the name of another cursor that is announced via the AS CURSOR clause by a FOR SELECT cursor However a cursor can share its name with any other type of variable within the same context since the operations available to each are different Positioned updates and deletes with cursors using the WHERE CURRENT OF clause are al lowed Attempts to fetch from or close a FO
128. library link for libgds so between the multithreaded libfbclient so and the single threaded libfbembed so library that allows an embedded direct open of the db file For compatibility with previous installs libgds so by default points to libfbembed so Linux Server Tips Embedded or direct access to database files The Classic install offers an embedded mode of access that allows programs to open database files directly To operate in this mode a database enabled user requires privileged access to some of the Firebird configuration and status files Now that it is the firebird user not root that is the default user to run the software you need to know how to get a user into the firebird group to enable direct access to databases It is documented in the readme notes but the following steps should get you where you need to be To add a user e g skywalker to the firebird group the root user needs to do usermod G firebird skywalker Next time skywalker logs on he can start working with firebird databases To list the groups that a user belongs to type the following at the command line groups 120 INSTALLATION NOTES Uninstalling on Linux If you need to uninstall do it as root user The following examples use Classic server but the same holds true for SuperServer by replacing the CS with SS Uninstalling an RPM package For rpm packages Srpm e FirebirdCS 2 0 0 Uninstalling a tarball install
129. line of the statement that caused the failure related to the whole script This feature works even if there are nested scripts namely if script SA includes script SB and SB causes a failure the line number is related to SB When SB is read completely isql continues execut ing SA and then isql continues counting lines related to SA since each file gets a separate line counter script SA includes SB when SA uses the INPUT command to load SB Lines are counted according to what the underlying IO layer considers separate lines For ports using EDITLINE a line is what readline provides in a single call The line length limit of 32767 bytes re mains unchanged Enhanced Command line Help M Kubecek When unknown parameters are used isql now shows all of the command line parameters and their ex planations instead of just a simple list of allowed switches opt firebird bin isql Unknown switch usage isql options lt database gt a all extract metadata incl legacy non SQL tables b ail bail on errors set bail on c ache num number of cache buffers ch arset lt charset gt connection charset set names d atabase lt database gt database name to put in script creation e cho echo commands set echo on ex tract extract metadata i nput lt file gt input file set input m erge merge standard error m2 merge diagnostic n oautocommit no aut
130. lowing are the updated notes The embedded server is a fully functional server linked as a dynamic library fbembed dll It has ex actly the same features as the usual Superserver and exports the standard Firebird API entrypoints The embedded server acts as a true local server for a single client accessing databases on a local ma chine It can also act as a remote gateway that redirects all network calls to other hosts just as the reg ular client library does Registry The Firebird Registry entries are ignored The root directory of the embedded server is the same dir ectory as the one where the embedded library binary is located Database Access Client access can be only via the local XNET protocol i e NOT a TCP IP local loopback connec tion string that includes the server name localhost or the IP address 127 0 0 1 The embedded server supports only the local connect to an absolute database file path without a server name The client program gets exclusive access to the database file after successful connect 113 INSTALLATION NOTES Authentication and Security The security database security2 fdb is not used in connecting to the embedded server Hence it is not required Any user is able to attach to any database Since both the server and the client run in the same address space security becomes just an agreement between the accessor and the accessed which can be easily compromised Note SQL privileg
131. ly active transactions isc_info_creation_date Returns the date and time when the database was re created To decode the returned value call isc_vax_integer twice to extract first the date and second the time portions of the ISC_TIMESTAMP Then use isc decode timestamp as usual Additions to the isc transaction info Structure V Horsun The following items have been added to the isc transaction info function call structure isc info tra oldest interesting Returns the number of the oldest interesting transaction when the current transaction started For snapshot transactions this is also the number of the oldest transaction in the private copy of the trans action inventory page TIP isc info tra oldest active Foraread committed transaction returns the number of the current transaction For all other transactions returns the number of the oldest active transaction when the current transaction started isc info tra oldest snapshot Returns the number of the lowest tra oldest active of all transactions that were active when the current transaction started 13 Changes to the Firebird API and ODS Note This value is used as the threshold high water mark for garbage collection isc_info_tra_isolation Returns the isolation level of the current transaction The format of the returned clumplets is isc_info_tra_isolation 1 isc_info_tra_consistency isc_info_tra_concurrency
132. n Limits Increased N Samofatov 40 bit 64 bit internally record enumerators have been introduced to overcome the 30GB table size limit imposed by 32 bit record enumeration Debugging Improvements Various Contributors Improved Reporting from Bugchecks BUGCHECK log messages now include file name and line number A Brinkman Updated Internal Structure Reporting Routines that print out various internal structures DSQL node tree BLR DYN etc have been up dated N Samofatov New Debug Logging Facilities Thread safe and signal safe debug logging facilities have been implemented N Samofatov Diagnostic Enhancement Syslog messages will be copied to the user s tty if a process is attached to it A Peshkov Improved Connection Handling on POSIX Superserver A Peshkov Posix SS builds now handle SIGTERM and SIGINT to shutdown all connections gracefully A Peshkov New in Firebird 2 0 PSQL Invariant Tracking Reworked N Samofatov Invariant tracking in PSQL and request cloning logic were reworked to fix a number of issues with re cursive procedures for example SF bug 627057 Invariant tracking is the process performed by the BLR compiler and the optimizer to decide whether an invariant an expression which might be a nested subquery is independent from the parent con text It is used to perform one time evaluations of such expressions and then cache the result If some invariant is not determ
133. n implementation of the MATCHES predicate in GDML fixed by D Yemanov SF bug 1404215 Column dependencies were not being stored for views fixed by D Yemanov SF bug 1191206 A few constraint issues fixed by D Yemanov SF bug 609538 Alter Index on a Foreign Key index should cause an exception and it did but the error message was not appropriate fixed by D Yemanov SF bug 1175157 An error in the thread scheduler was causing the server to lock up fixed by V Horsun Not registered 127 Bugs Fixed 1 Improper thread data operations were occurring during the protocol port cleanup 2 Transaction rollback and attachment cleanup for broken TCP connections was faulty fixed by V Horsun D Yemanov Not registered A wrong error message was decoded when firebird msg was missing or outdated fixed by D Yemanov Not registered Buffer overflows inside the BLR gt ASCII blob filter were causing memory cor ruption and server crashes fixed by D Yemanov Not registered A successful status vector could be reported to the user after a failed DDL opera tion fixed by V Horsun Not registered Threading issues in the DSQL metadata cache were causing unexpected invalid transaction handle errors under load fixed by D Yemanov Not registered Wrong results would be returned by the division operation after DDL changes Example create table test fld numeric 18 2 insert into test fld values 1 commit
134. n t obey the declared type for a parameter it will simply send whatever data it has for that parameter so the UDF is left to decide whether to reject the result or to try to convert the parameter to the expected data type Since UDFs have no formal mechanism to signal errors the returned value would have to be used as an indicator The basic problem was to keep the simplicity of the typical declarations no descriptors while at the same time being able to signal null The engine normally passed UDF parameters by reference In practical terms that means passing a pointer to the data to tell the UDF that we have SQL NULL However we could not impose the risk of crashing an unknown number of different existing public and private UDFs that do not expect NULL The syntax had to be enhanced to enable NULL handling to be requested explicitly The solution therefore is to restrict a request for SQL NULL signaling to UDFs that are known to be capable of dealing with the new scenario To avoid adding more keywords the NULL keyword is ap pended to the UDF parameter type and no other change is required Example declare external function sample int null returns int by value If you are already using functions from ib udf and want to take advantage of null signaling and null recognition in some functions you should connect to your desired database run the script 90 External Functions UDFs misc upgrade ib_udf_upgrade
135. nation operations have been checked for the possibility that the res ulting string might exceed the string length limit of 32 000 bytes i e overflow This check was per formed during the statement prepare using the declared operand sizes and would throw an error for an expressions such as CAST qwe AS VARCHAR 30000 CAST rty AS VARCHAR 30000 From Firebird 2 0 onward this expression throws only a warning at prepare time and the overflow check is repeated at runtime using the sizes of the actual operands The result is that our example will be executed without errors being thrown The isc concat overflow exception is now thrown only for actual overflows thus bringing the behaviour of overflow detection for concatenation into line with that for arithmetic operations Changes to Synchronisation Logic N Samofatov 1 Lock contention in the lock manager and in the SuperServer thread pool manager has been re duced significantly 2 A rare race condition was detected and fixed that could cause Superserver to hang during re quest processing until the arrival of the next request 3 Lock manager memory dumps have been made more informative and OWN hung is detected correctly 4 Decoupling of lock manager synchronization objects for different engine instances was imple New in Firebird 2 0 mented Support for 64 bit Platforms A Peshkov N Samofatov Firebird 2 0 will support 64 bit platforms Record Enumeratio
136. nclude 87 Command line Utilities gsec return code C Valderrama gsec now returns an error code when used as a non interactive utility Zero indicates success any oth er code indicates failure GFix Server Utility Changes to the gfix utility include New Shutdown States Modes N Samofatov D Yemanov The options for gfix shut down have been extended to include two extra states or modes to govern the shutdown New Syntax Pattern gfix lt command gt lt state gt lt options gt command shut online lt state gt normal multi single full options force timeout tran attach normal state online database multi state multi user shutdown mode the legacy one unlimited attachments of SYSDBA own er are allowed single state single user shutdown only one attachment is allowed used by the restore process full state full exclusive shutdown no attachments are allowed Note Multi is the default state for shut normal is the default state for online The modes can be switched sequentially normal lt gt multi lt gt single lt gt full Examples gfix shut single force 0 gfix shut full force 0 gfix online single gfix online You cannot use shut to bring a database one level more online and you cannot use online to make a database more protected an error will be thrown 88
137. neral Notes The v 2 0 release cycle of Firebird brings with it a large collection of long awaited enhancements un der the hood that significantly improve performance security and support for international languages Several annoying limitations along with a huge pile of old bugs inherited from the legacy code have gone Many of the command line tools have been refurbished and this release introduces the all new incremental backup tools NBak and NBackup The old 252 bytes or less limit on index size is gone for good replaced by much extended limits that depend on page size Calculation of index statistics has been revamped to improve the choices the optimizer has available especially for complex outer join distributions and DISTINCT queries Many new additions have been made to the SQL language including support for derived tables SELECT FROM SELECT FROM PSQL blocks in dynamic SQL through the new EX ECUTE BLOCK syntax and some handy new extensions in PSQL itself Before you read on to find out about all of these new features please take a moment to note some points about approaching this new release Back Up The on disk structure ODS of the databases created under Firebird has changed Although Firebird 2 0 will connect to databases having older ODS versions most of the new features will not be avail able to them Make transportable gbak backups of your existing databases including your old security fdb or even
138. nning of the result set for descending sorts NULLs are placed at the end of the result set Important In former versions NULLs were always on top If you have client code or PSQL definitons that rely on the legacy NULLs placement it will be necessary to use the NULLS FIRST option in your ORDER BY clauses CURRENT TIMESTAMP now returns milliseconds by default The context variable CURRENT TIMESTAMP now returns milliseconds by default while it truncated sub seconds back to seconds in former versions If you need to continue receiving the truncated value you will now need to specify the required accuracy explicitly i e specify CURRENT TIMESTAMP 0 ORDER BY lt ordinal number gt now causes SELECT expansion When columns are referred to by the ordinal number degree in an ORDER BY clause when the output list uses SELECT FROM syntax the column list will be expanded and taken into account when determining which column the number refers to This means that now SELECT T1 T2 COL FROM T1 T2 ORDER BY 2 sorts on the second column of table T1 while the previous versions sorted on T2 COL Tip This change makes it possible to specify queries like SELECT FROM TAB ORDER BY 5 Configuration Parameters Configuration parameter DeadThreadsCollection is deprecated The parameter DeadThreadsCollection for Superserver in firebird conf is deprecated and will be ignored i
139. not track old record versions This reverts GC behaviour to that of IB 5 6 and earlier It is the only option for Classic background garbage collection will be performed only by background threads as is the case for Firebird 1 5 and earlier User table scan requests will not remove unused record versions but will cause the GC thread to be notified about any page where an unused record version is detected The engine will also remember those page numbers where UPDATE and DELETE statements created back versions combined the installation default for Superserver both background and cooperative garbage col lection are performed Note The Classic server ignores this parameter and always works in cooperative mode Porting of the Services API to Classic is Complete N Samofatov Porting of the Services API to Classic architecture is now complete All Services API functions are now available on both Linux and Windows Classic servers with no limitations Known issues with gsec error reporting in previous versions of Firebird are eliminated Lock Timeout for WAIT Transactions A Karyakin D Yemanov All Firebird versions provide two transaction wait modes NO WAIT and WAIT NO WAIT mode means that lock conflicts and deadlocks are reported immediately while WAIT performs a blocking wait which times out only when the conflicting concurrent transaction ends by being committed or rolled back The new feature extends the
140. now it contains a patch by Ivan Prenosil with some minor differences enabling any user to change his her own password In firebird 1 5 the table USERS has to be readable by PUBLIC an engine requirement without which the password validation process would fail Ivan s patch solution used a view with the con dition WHERE USER That worked due to another bug in the engine that left the SQL vari able USER empty not authenticator as it might seem from engine s code 75 Security in Firebird 2 Once that bug was fixed it was certainly possible to add the condition USER authenticator For the short term that was OK because the username is always converted to upper case A better solution was found that avoids making user authentication depend on an SQL trick The result is that the non SYSDBA user can see only his own login in any user management tool gsec or any graphical interface that use the Services API SYSDBA continues to have full access to manage users accounts New security database structure The Firebird 2 security database is named security2 fdb For user authentication it has a new ta ble named RDBSUSERS that stores the new hashed passwords A view over this table replaces the old USERS table and enables users to change their own passwords The DDL for the new structures can be found in the Security Upgrade Script in the Appendix gsec in Firebird 2 Special measures were thus taken to
141. ns in its parameters Formerly the inbuilt SUBSTRINGY function accepted only constants as its second and third argu ments start position and length respectively Now the arguments can be anything that resolves to a value including host parameters function results expressions subqueries etc Note The length of the resulting column is the same as the length of the first argument This means that in the following x varchar 50 substring x from 1 for 1 the new column has a length of 50 not 1 Thank the SQL standards committee Enhancements to NULL Logic The following features involving NULL in DSQL have been implemented NULL NULL Can Return True for DISTINCT Test O Loa D Yemanov A new equivalence predicate behaves exactly like the equality inequality predicates but tests whether one value is distinct from the other Thus it treats NULL NULL as TRUE It is available in both DSQL and PSQL Syntax Pattern lt value gt IS NOT DISTINCT FROM lt value gt Examples 1 SELECT FROM T1 JOIN T2 ON T1 NAME IS NOT DISTINCT FROM T2 NAME Ne 28 Data Manipulation Language DML SELECT FROM T WHERE T MARK IS DISTINCT FROM test Note Points to note 1 Because the DISTINCT predicate considers that two NULL values are not distinct it never evaluates to the truth value UNKNOWN Like the IS NOT NULL predicate it can only be True or Fals
142. nvir onmentVariable fixed by C Valderrama Indexing amp Optimization SF 459059D Index breaks ANY result MORE INFO REQUIRED fixed by N Samofatov Not registered Ambiguous queries were still possible under some conditions fixed by A Brinkman SF 735720 SELECT STARTING WITH v was wrong when v fixed by A Brinkman Not registered There were issues with negative dates i e those below Julian date zero when stored in indices fixed by A Brinkman 138 Bugs Fixed SF 1211354 Redundant evaluations were occurring in COALESCE fixed by A Brinkman Not registered Error index key too big would occur when creating a descending index fixed by V Horsun SF 1242982 Bug in compound index key mangling fixed by A Brinkman Vulnerabilities SF 1466193 Semaphore arrays permissions in fb lock mgr were 0666 i e anyone could lock them and block all subsequent queries fixed by A Peshkov Not registered Possible buffer overflow in WNET fixed by A Peshkov Not registered Several buffer overflows were fixed fixed by A Peshkov SF 1155520 Fixed a vulnerability that could make it possible for a user who was neither SYSD BA nor owner to create a database that would overwrite an existing database fixed by A dos Santos Fernandes ISQL Bugs SF 781610 Comments in ISQL using were causing problems fixed by J Bellardo B Rodriguez Samoza 139 Bugs Fixed Not registered ISQ
143. o account for creating new databases 1 the user firebird has to have write permission to the directory in which you want to create the database 2 the recommended value of the DatabaseAccess attribute in the opt firebird firebird conf file should be set to None to permit access only through entries in the aliases conf file 3 use entries in aliases conf to abstract users from the physical locations of databases More notes 118 INSTALLATION NOTES on aliases are to be found in the topic Database File Aliasing Procedures for creating a new database can vary with different configurations but the following con figuration and steps are recommended 1 If a directory that is owned by the user firebird does not exist then change to root user and cre ate the directory su root mkdir p var firebird Schown firebird firebird var firebird Create a new physical database and set up an alias entry to point to it As root or firebird user run the following script cd opt firebird bin createAliasDB sh test fdb var firebird test fdb Usage is createAliasDB sh lt dbname gt lt pathtodb gt As an alternative for step 2 the steps in the createAliasDB sh script can be performed manually by Svi opt firebird aliases conf and add the line at the end of the file test fdb var firebird test fdb Then create the database opt firebird bin isgl u sysdba p lt password gt SQL gt cr
144. o load Supporting legacy applications and drivers Traditionally applications that use InterBase or Firebird have expected to load the gds32 dll client lib rary from the system directory Firebird 2 0 ships with a tool named instclient exe that can install a clone of fbclient dll to the Windows System directory This clone gets patched on the fly so that its file version information begins with 6 3 to provide compatibility for old applications that check the GDS32 DLL file version and can not make sense of a number string such as 2 0 InstClient exe Tool This instclient exe tool can also install the FBCLIENT DLL itself in the Windows system directory if required This will take care of tools or applications that need to load it from there The instclient exe utility should be located in the bin directory of your Firebird installation and must be run from there in a command shell Usage of instclient exe instclient i nstall f orce library q uery library r emove library where library is bclient gds32 z can be used with any other option prints version Version information and shared library counts are handled automatically You may provide the f orce option to override version checks Caution If you f orce the installation it could break another Firebird or InterBase version already in stalled You might have to reboot the machine in order to finalize the copy For more det
145. ocommit DDL set autoddl off now arnings do not show warnings o utput file output file set output pag elength size page length p assword password connection password q uiet do not show the message Use CONNECT r ole role role name r2 role role uses quoted identifier sqidialect dialect SOL dialect set sql dialect t erminator term command terminator set term u ser user user name X extract metadata k show program and server version 86 Command line Utilities ISQL Bugs Fixed SF 910430 ISQL and database dialect fixed by C Valderrama B Rodriguez Somoza What was fixed When ISQL disconnected from a database either by dropping it or by trying to connect to a non existent database it remembered the SQL dialect of the previous connection which could lead to some inappropriate warning messages SF 223126 Misplaced collation when extracting metadadata with ISQL fixed by B Rodriguez Somoza SF 223513 Ambiguity between tables and views fixed by B Rodriguez Somoza SF 518349 ISQL SHOW mangles relationship fixed by B Rodriguez Somoza Unregistered bug Possible crashes with long terminators fixed by C Valderrama Unregistered bug Avoided several SQL gt prompts when using the INPUT command interact ively implemented by C Valderrama Unregistered bugs Some memory leaks fixed by C Valderrama gsec Authentication Manager Changes to the gsec utility i
146. on messages increased V Horsun Maximum size of exception messages raised from 78 to 1021 bytes New Description Field for Generators C Valderrama Added RDB DESCRIPTION to RDB GENERATORS so now you can include description text when creating generators New Description Field for SQL Roles C Valderrama Added RDB DESCRIPTION and RDB SYSTEM_FLAG to RDB ROLES to allow description text and to flag user defined roles respectively ODS Type Recognition N Samofatov Introduced a concept of ODS type to distinguish between InterBase and Firebird databases Smarter DSQL Error Reporting C Valderrama The DSQL parser will now try to report the line and column number of an incomplete statement New Column in RDB Index_Segments D Yemanov A Brinkman A new column RDB STATISTICS has been added to the system table RDB INDEX_SEGMENTS to store the per segment selectivity values for multi key indexes 15 Changes to the Firebird API and ODS Note The column of the same name in RDB INDICES is kept for compatibility and still represents the total index selectivity that is used for a full index match 16 Data Definition Language DDL New and Enhanced Syntaxes The following statement syntaxes and structures have been added to Firebird 2 CREATE SEQUENCE D Yemanov SEQUENCE has been introduced as a synonym for GENERATOR in accordance with SQL 99 SE QUENCE is a syntax term described
147. on overflow c If any data type in DTS is approximate numeric then each data type in DTS shall be numer ic else an error is thrown d If some data type in DTS is a date time data type then every data type in DTS shall be a date time data type having the same date time type e If any data type in DTS is BLOB then each data type in DTS shall be BLOB and all with the same sub type UNIONs Allowed in ANY ALL IN Subqueries D Yemanov The subquery element of an ANY ALL or IN search may now be a UNION query IIF Expression Syntax Added O Loa IIF search condition lt valuel gt lt value2 gt is implemented as a shortcut for CASE WHEN search condition THEN lt valuel gt ELSE value2 END It returns the value of the first sub expression if the given search condition evaluates to TRUE other wise it returns a value of the second sub expression Example SELECT IIF VAL gt 0 VAL VAL FROM OPERATION CAST Behaviour Improved D Yemanov The infamous Datatype unknown error SF Bug 1371274 when attempting some castings has been eliminated It is now possible to use CAST to advise the engine about the data type of a paramet er 27 Data Manipulation Language DML Example SELECT CAST AS INT FROM RDBSDATABASE Built in Function SUBSTRING Enhanced O Loa D Yemanov The built in function SUBSTRINGO can now take arbitrary expressio
148. on returns a value of 1 if the variable existed before the call and 0 otherwise e To delete a variable from a context set its value to NULL Pre defined Namespaces A fixed number of pre defined namespaces is available USER SESSION Offers access to session specific user defined variables You can define and set values for variables with any name in this context USER TRANSACTION Offers similar possibilities for individual transactions SYSTEM Provides read only access to the following variables NETWORK PROTOCOL The network protocol used by client to connect Currently used val ues TCPv4 WNET XNET and NULL CLIENT ADDRESS The wire protocol address of the remote client represented as a string The value is an IP address in form xxx xxx xxx xxx for TCPv4 protocol the local process ID for XNET protocol and NULL for any other protocol DB NAME Canonical name of the current database It is either the alias name 1f connection via file names is disallowed DatabaseAccess NONE or otherwise the fully expanded database file name J SOLATION LEVEL The isolation level of the current transaction The returned value will be one of READ COMMITTED SNAPSHOT CONSISTENCY TRANSACTION ID The numeric ID of the current transaction The returned value is the same as would be returned by the CURRENT TRANSACTION pseudo variable SESSION ID The numeric ID of the current session The return
149. onnect all client connections as discussed in the Borland Inter Base 6 beta Data Definition Guide DataDef pdf in the section Altering and dropping procedures in use Examples CONNECT SET TERM CREATE PROCEDURE P1 X INTEGER 123 RETURNS Y INTEGER A B 48 Stored Procedure Language PSQL FROM Pl X E 123 XECUTE PROCEDURE P1 NG E C S S WSU 123 ET TERM REATE PROCEDURE P2 E TURNS S EGIN FOR S DO SU ND OMMIT Y INTEGER ELECT Y FROM Pl INTO Y SPEND ET TERM ELECT FROM P2 Y S A A B E ic S S LTER P S EGIN SUSPEN ND OMMIT Y ex 123 ET TERM ROCEDURE P1 X INTEGE RETURNS Y INTEGER r D ET TERM ELECT FROM Pl Y 5875 ELECT FROM P2 Y C C S OMMIT ONNECT 123 r ELECT FROM P2 49 R CURRENT TRANSACTION Stored Procedure Language PSQL 5880 Note The source and BLR for the argument defaults are stored in RDB FIELDS LEAVE lt label gt Syntax Support D Yemanov New LEAVE lt label gt syntax now allows PSQL loops to be marked with l
150. ot own a copy of The Firebird Book by Helen Borrie then you will also need to find the beta documentation for InterBase 6 0 It consists of several volumes in PDF format of which the most useful will be the Language Reference LangRef pdf and the Data Definition Guide DataDef pdf The Firebird Project is not allowed to distribute these documents but they are easily found at several download sites on the Web using Google and the search key LangRef pdf When you find one you usually find them all The Firebird Project Chapter 2 New in Firebird 2 0 Derived Tables A Brinkman Implemented support for derived tables in DSQL subqueries in FROM clause as defined by SQL200X A derived table is a set derived from a dynamic SELECT statement Derived tables can be nested if required to build complex queries and they can be involved in joins as though they were normal tables or views More details under Derived Tables in the DML chapter PSQL Now Supports Named Cursors D Yemanov Multiple named i e explicit cursors are now supported in PSQL and in DSQL EXECUTE BLOCK statements More information in the chapter Explicit Cursors Reimplemented Protocols on Windows D Yemanov Two significant changes have been made to the Windows only protocols Local Protocol XNET Firebird 2 0 has replaced the former implementation of the local transport protocol often referred to as IPC or IPServer with a new one named XNE
151. oth er BLOB INTL Plug ins Character sets and collations are installed using a manifest file The manifest file should be put in the rootdir intl with a conf extension It is used to locate character sets and collations in the libraries If a character set collation is declared more than once it is not loaded and the error is reported in the log The symbol this is used to indicate the same directory as the manifest file and the library extension should be omitted Example of a Section from fbintl conf intl module fbintl filename this fbintl intl module charset ISO8859 1 intl module fbintl collation ISO8859 1 collation DA DA collation DE DE collation EN UK collation EN US collation ES ES collation PT BR collation PY PI charset charset WIN1250 intl module fbintl collation WIN1250 collation PXW CSY collation PXW HUN collation PXW HUNDC charset New Character Sets Collations UTF8 character set The UNICODE_FSS character set has a number of problems it s an old version of UTF8 that accepts malformed strings and does not enforce correct maximum string length In FB 1 5 X UTFS is an alias to UNICODE FSS 68 New Features for Text Data Now UTF 8 is a new character set without the inherent problems of UNICODE_FSS UNICODE collations for UTF8 UCS_BASIC works identically to UTF8 with no collation sp
152. otice that this means that you may have only one architecture of the engine either fbserver exe Superserver or fb inet server exe the parent process for Classic installed as a service The Control Panel applet is not installed with Classic deliberately Don t try to install and use it The concept of terminating a service does not apply to the Classic model Simplified setup If you don t need a registered service then you may avoid running both instreg exe and instsvc exe In this case you should just unzip the archive into a separate directory and run the server as an applica tion fbserver exe a It should treat its parent directory as the root directory in this case Uninstallation To remove FB 1 5 without a Windows Uninstaller you should stop the server run instreg exe remove run instsvc exe remove delete installation directory delete fbclient dll and gds32 dll from the OS system directory Other Win32 Issues Winsock2 Firebird requires WinSock2 All Win32 platforms should have this except for Win95 A test for 112 INSTALLATION NOTES the Winsock2 library is made during install If it is not found the install will fail To find out how to go about upgrading visit this link Windows ME and XP Windows ME and XP Home and Professional editions there is a feature called System Restore that causes auto updating backup caching of all files on the system having a gdb suffix The
153. pen STOP ANY FIREBIRD OR INTERBASE SERVER THAT IS RUNNING The installer will try to detect if an existing version of Firebird or InterBase is installed and or run ning In a non installer install you are on your own Provided you do not have a FIREBIRD environment variable defined the default root location of Firebird 2 0 will be C Program Files Firebird Firebird_2_0 For installing Firebird as a service if you want to make use of the secure login feature create a firebird service user on the system any name and password you like as an ordinary user with appropriate privileges You should read the document named README instsvc txt first If you have a zip kit you will find it in the doc directory of the zipfile s root If you don t have a zip kit available the file won t be available until after the installation You can read the same document at this URL http fire bird cvs sourceforge net viewcvs py firebird firebird2 doc READMBE instsvc Naming databases on Windows Note that the recommended extension for database files on Windows ME and XP is fdb to avoid possible conflicts with System Restore feature of these Windows versions Failure to address this is sue on these platforms will give rise to the known problem of delay on first connection to a database whose primary file and or secondary files are named using the gdb extension that used to be the 106 INSTALLATION NOTES Borland convention for suffi
154. r zero it can be made to work with a simple SELECT statement Example SQL gt select rdbSset_context USER_SESSION Nickolay ru CNT gt from rdb database RDBSS ET_CONTEXT 0 0 means not defined already we have set it to ru SQL gt select rdbSset_context USER_SESSION Nickolay ca CNT gt from rdb database RDBSS ET CONTEXT 34 Data Manipulation Language DML 1 means it was defined already we have changed it to ca SQL gt select rdbSset_context USER_SESSION Nickolay NULL CNT gt from rdb database RDBSSET CONTI Cl XT 1 1 says it existed before we have changed it to NULL i e undefined it SQL gt select rdb set context USER SESSION Nickolay NULL CNT gt from rdb database RDBSSET_CONTEXT 0 0 since nothing actually happened this time it was already undefined Improvements in Handling User specified Query Plans D Yemanov 1 Plan fragments are propagated to nested levels of joins enabling manual optimization of com plex outer joins 2 Auser supplied plan will be checked for correctness in outer joins 3 Short circuit optimization for user supplied plans has been added 4 Auser specified access path can be supplied for any SELECT based statement or clause Syntax rules The following schema describing the syntax rules should be helpful when composing p
155. refully before opening port 3050 to the Internet An important security problem with Firebird still remains unresolved the transmission of poorly en crypted passwords in clear across the network It is not possible to resolve this problem without breaking old clients To put it another way a user who has set his her password using a new secure method would be un able to use an older client to attach to the server Taking this into account with plans to upgrade some aspects of the API in the next version the decision was made not to change the password transmission method in Firebird 2 0 The immediate problem can be solved easily by using any P tunneling software such as ZeBeDee to move data to and from a Firebird server for both 1 5 and 2 0 It remains the recommended way to access your remote Firebird server across the Internet Dealing with the New Security Database A Peshkov If you try to put a pre Firebird 2 security database security fdb or a renamed isc4 gdb into Fire bird s new home directory and then try to connect to the server you will get the message Cannot at tach to password database It is not a bug it is by design A security database from an earlier Firebird version cannot be used directly in Firebird 2 0 or higher The newly structured security database is named security2 fdb In order to be able to use an old security database it is necessary to run the upgrade script secur ity_database sql
156. remental backups are multi level That means if you do a Level 2 backup every day and a Level 3 backup every hour each Level 3 backup contains all pages changed from the beginning of the day till the hour when the Level 3 backup is made Backing Up Creating incremental backups has the following algorithm 1 Issue ALTER DATABASE BEGIN BACKUP to redirect writes to the difference file 2 Lookup the SCN and GUID of the most recent backup at the previous level 3 Stream database pages having SCN larger than was found at step 2 to the backup file 4 Write the GUID of the previous level backup to the header to enable the consistency of the backup chain to be checked during restore 5 Issue ALTER DATABASE END BACKUP 6 Add a record of this backup operation to RDBSBACKUP_HISTORY Record current level SCN snapshot GUID and some miscellaneous stuff for user consumption Restoring Restore is simple we reconstruct the physical database image for the chain of backup files checking that the backup_guid of each file matches prev_guid of the next one then fix it up change its state in header to nbak_state_normal Usage nbackup lt options gt 80 Command line Utilities Valid Options L database Lock database for filesystem copy N database Unlock previously locked database F database Fixup database after filesystem copy B level database filename
157. repare to revert to the regular build and set up to export the LD ASSUME KERNEL 2 2 5 variable if the 2 4 im plementation of the NPTL causes problems Details for doing this follow below e 64 bit builds are available for both Classic and Superserver These should be installed only on a 64 bit Linux system NPTL support is native on 64 bit Linux Setting Linux to Use the Old Threading Model If the NPTL causes problems for SuperServer and locally compiled programs including utilities such as gbak throwing a Broken Pipe error you can try to solve the problem by forcing Linux to use the old threading model To fix 1 In etc init d firebird LD_ASSUME_KERNEL 2 2 5 export LD_ASSUME_KERNEL That takes care of the server instance 2 You need to have the LD_ASSUME_KERNEL environment variable set up within the local envir onment as well so add the following to etc profile to ensure every user picks it up for the com mand line utilities after HISTSIZE 1000 add LD_ASSUME_KERNEL 2 2 5 On the following line export it this is all in one line 116 INSTALLATION NOTES export PATH USER LOGNAME MAIL HOSTNAME HISTSIZE INPUT_RC LD_ASSUME_KERNEL Installing on Linux The following instructions describe the Classic installation For installation of Superserver the CS in the package name is replaced by SS For example the package FirebirdCS
158. rom A 1 null SOL select a from A null 1 gnull gnull gnull gnull gnull order order order order order by by by by by CROSS JOIN is Now Supported D Yemanov a desc a asc nulls first a asc nulls last a desc nulls last a desc nulls first CROSS JOIN is now supported Logically this syntax pattern A CROSS JOIN B is equivalent to either of the following A INNI ER JOIN B ON 1 21 or simply FROM A x B 30 Data Manipulation Language DML Subqueries and INSERT Statements Can Now Accept UNION Sets D Yemanov SELECT specifications used in subqueries and in INSERT INTO lt insert specification gt SELECT statements can now specify a UNION set New Extensions to UPDATE and DELETE Syntaxes O Loa ROWS specifications and PLAN and ORDER BY clauses can now be used in UPDATE and DE LETE statements Users can now specify explicit plans for UPDATE DELETE statements in order to optimize them manually It is also possible to limit the number of affected rows with a ROWS clause optionally used in combination with an ORDER BY clause to have a sorted recordset Syntax Pattern UPDATE SET WHERE PLAN plan items gt ORDER BY value list gt ROWS value TO value or DELETE FROM PLAN plan items gt ORDER BY lt value list gt ROWS value TO l
159. rting out with Firebird either will do although the Classic server is likely to prove a better platform for initially experimenting with Firebird READ THIS FIRST You will need to be root user to install Firebird Installation on Linuxen requires a glibc package installed that is equal to or greater than glibc 2 2 5 and a libstdc so equal to or greater than libstdc 5 0 115 INSTALLATION NOTES Note Some higher distros e g Mandriva 10 2 might fail to complete the password setting script at the end of a Classic installation because the local client libfbembed so needs libstdc so 5 and the installed version of this runtime is missing An impure solution that should solve the immedi ate problem at least is to Google for compat libstdc and find one that was built for your kernel version The pure solution of course is to compile Firebird on the same system that you are going to run it on This might be necessary anyway if the compatibility runtimes cause problems with other applications Do not try to use rpm update to bring any existing Firebird package installation up to date The Firebird packages do not support it If you are installing Superserver on a Linux that supports the new POSIX threading library NPTL then choose the NPTL build of Firebird Most distros with the 2 6 kernel are built with NPTL enabled some with later 2 4 kernels also enabled it but it may be wise to p
160. se install it is highly recommended to use the installer if there is one available Use gbak to back up your old security fdb or for a previous Firebird 1 0 installation isc4 gdb se curity database You can restore it later as security2 fdb using the directions in the chapter entitled New Security Features If you have special settings in your existing firebird conf ibconfig for Firebird 1 0 there may be some values that you want to transfer to equivalent parameters in the new firebird conf When you use the Windows control panel applet Add Remove Programs to uninstall Firebird 1 5 x recommended the uninstaller should preserve your existing firebird conf and aliases conf However it won t hurt to take the precaution of backing up these files to your home directory The Firebird 1 0 x ibconfig file if applicable should certainly be backed up Note If you are upgrading from Firebird 1 0 x go to the Downloads Firebird Database Engine page at the Firebird website and download the Firebird 1 5 3 releasenotes for details of the correlation between settings in ibconfig and firebird conf Study the notes about firebird conf to work out what can be copied directly and what parameters require new syntax When reinstalling Firebird 2 0 certain configuration files in the installation directory will be pre served if you run the installer and OVERWRITTEN if you decompress a zip kit into the default location The files are se
161. sql that is in the Firebird directory and commit after wards Caution It is recommended to do this when no other users are connected to the database The code in the listed functions in that script has been modified to recognize null only when NULL is signaled by the engine Therefore starting with FB v2 rtrim ltrim and several other string functions no longer assume that an empty string means a NULL string The functions won t crash if you don t upgrade they will simply be unable to detect NULL If you have never used ib udf in your database and want to do so you should connect to the database run the script udf ib_udf2 sql preferably when no other users are connected and commit afterwards Note Note the 2 at the end of the name The original script for FB v1 5 is still available in the same directory UDF library diagnostic messages improved A Peshkov Diagnostics regarding a missing unusable UDF module have previously made it hard to tell whether a module was missing or access to it was being denied due to the UDFAccess setting in firebird conf Now we have separate understandable messages for each case UDFs Added and Changed UDFs added or enhanced in Firebird 2 0 s supplied libraries are IB UDF rand vs IB UDF srand F Schlottmann Goedde In previous versions the external function rand sets the random number generator s starting point based on the current time and then
162. sults log m m2 Tip However if the user loads isq interactively and later executes a script with the input command this is considered an interactive session even though isql knows it is executing a script Example isql Use CONNECT or CREATE DATABASE to specify a database SQL gt set bail SQL gt input my_fb sql SOL Z Whatever contents the script has it will be executed completely errors and all even if the BAIL option is enabled m2 to Output Stats and Plans C Valderrama This is a command line option M2 to send the statistics and plans to the same output file as the other output via the o utput switch When the user specifies that the output should be sent to a file two possibilities have existed for years either atthe command line the switch o followed by a file name is used the command OUTput followed by a file name is used either in a batch session or in the interact ive isql shell In either case simply passing the command OUTput is enough to have the output returned to the console However although error messages are shown in the console they are not output to the file The m command line switch was added to meld mix the error messages with the normal output to wherever the output was being redirected This left still another case statistics about operations SET STATs command and SQL plans as the server returns them SET PLAN and SET PLANONLY commands h
163. t value gt New Context Variables A number of new facilities have been added to extend the context information that can be retrieved Sub second Values Enabled for Time and DateTime Variables D Yemanov CURRENT TIMESTAMP NOW Now Return Milliseconds The context variable CURRENT TIMESTAMP and the date time literal NOW will now return the sub second time part in milliseconds Seconds Precision Enabled for CURRENT TIME and CURRENT TIMESTAMP CURRENT TIME and CURRENT TIMESTAMP now optionally allow seconds precision The feature is available in both DSQL and PSQL 31 Data Manipulation Language DML Syntax Pattern CURRENT TIME lt seconds precision gt CURRENT TIMESTAMP seconds precision gt Examples 1 SELECT CURRENT TIME FROM RDBSDATABASE 2 SELECT CURRENT TIME 3 FROM RDBSDATABASE 3 SELECT CURRENT TIMESTAMP 3 FROM RDBSDATABASE Note 1l The maximum possible precision is 3 which means accuracy of 1 1000 second one milli second This accuracy may be improved in the future versions 2 fno seconds precision is specified the following values are implicit e Ofor CURRENT TIME 3for CURRENT TIMESTAMP New System Functions to Retrieve Context Variables N Samofatov Values of context variables can now be obtained using the system functions RDBSGET CONTEXT and RDBSSET CONTEXT These new built in functions give access through SQL to some in
164. tered gbak could not restore a database containing broken foreign keys Now the restore continues to run the user gets a diagnostic indicating which FK caused the problem The affected index becomes inactive and after restore the database is left in shutdown state fixed by A Peshkov Not registered gbak would stall when used via the Services Manager and an invalid command line was passed fixed by V Horsun Not registered A computed column of a blob or array type would zero values in the first column of the table being restored fixed by D Yemanov Not registered Fixed some backup issues with stream BLOBs that caused them to be truncated under some conditions fixed by N Samofatov Not registered Interdependent views caused problems during the restore process fixed by A Brinkman SF 750659 If you want to start a fresh db you should be able to restore a backup done with the metadata only option Generator values were resisting metadata only backup and retaining latest val ues from the live database instead of resetting the generators to zero fixed by C Valderrama D Yemanov SF 908319 In v 1 5 wrong error messages would appear when using gbak with service mgr fixed by V Horsun SF 1122344 gbak kill option would drop an existing shadow fixed by D Yemanov Not registered gbak was adding garbage bytes to the SPB when called in the se rvice mgr mode 143 Bugs Fixed fixed by A dos Santos Fernandes
165. than to call the UDF General UDF Changes Build Changes C Valderrama Contributors The FBUDF library no longer depends on FBCLIENT to be built 92 Chapter 14 New Configuration Parameters and Changes ExternalFileAccess A Peshkov Modified in Firebird 2 to allow the first path cited in ExternalFilesAccess to be used as the default when a new external file is created LegacyHash A Peshkov This parameter enables you to configure Firebird 2 to reject an old DES hash always in an upgraded security database If you don t use the security database upgrade procedure this parameter does not affect Firebird operation A DES hash cannot arrive in the new security2 fdb Refer to the Security DB Upgrade Security section for instructions on upgrading your existing Fire bird 1 5 security fdb or a renamed isc4 gdb to the new security database layout The default value is true Redirection A Peshkov Parameter for controlling redirection of remote requests It controls the multi hop capability that was broken in InterBase 6 and is restored in Firebird 2 About Multi hop When you attach to some database using multiple hosts in the connection string only the last host in this list is the one that opens the database The other hosts act as intermediate gateways on port gds_db Previously when working this feature was available unconditionally Now it can be con figured Remote redirection is turned o
166. tring gt when b was blob and the engine was performing the conversion internally fixed by N Samofatov Not registered Materialization of BLOBs was not invalidating temporary BLOB IDs soon enough A blob is created as an orphan This blob has a blob id of 0 slot It is volatile meaning that if the connection terminates it will become eligible for garbage collection Once a blob is assigned to field in a table it is said to be materialized If the transaction that did the assignment commits the blob has an anchor in the table and will be considered permanent Its blob id is relation_id slot In situations where internal code is referencing the blob by its old volatile blob id the references are routed to the materialized blob until the session is closed fixed by N Samofatov Solution Now the references to a volatile blob are checked and when there are no more refer ences to it it is invalidated Not registered Conversion from string to blob had a memory leak fixed by N Samofatov SF 750664 Issues with read only databases and transactions fixed by N Samofatov Not registered When one classic process dropped a foreign key and another process was trying to delete master record the error partner index not found would be thrown fixed by V Horsun 125 Bugs Fixed Various server bugs 1 eliminated redundant attempts to get an exclusive database lock during shutdown 2 corrected inaccurate tim
167. ttern gfix command lt state gt lt options gt lt command gt gt shut online state normal multi single full options force timeout tran attach normal state online database e multi state multi user shutdown mode the legacy one unlimited attachments of SYSDBA owner are allowed single state single user shutdown only one attachment is allowed used by the restore process full state full exclusive shutdown no attachments are allowed For more details refer to the section on Gfix New Shutdown Modes in the Utilities chapter New in Firebird 2 0 UDFs Improved re NULL Handling C Valderrama Signalling SQL NULL Ability to signal SQL NULL via a NULL pointer see Signal SQL NULL in UDFs External function library ib udf upgraded to allow the string functions ASCII CHAR LOWER LPAD LTRIM RPAD RTIM SUBSTR and SUBSTRLEN to return NULL and have it inter preted correctly The script ib udf upgrade sql can be applied to pre v 2 databases that have these functions declared to upgrade them to work with the upgraded library This script should be used only when you are using the new ib udf library with Firebird v2 and operation requests are modified to anti cipate nulls Run time Checking for Concatenation Overflow D Yemanov Compile time checking for concatenation overflow has been replaced by run time checking From Firebird 1 0 onward concate
168. uperserver garbage collection changes Formerly Superserver performed only background garbage collection By contrast Classic per forms cooperative GC where multiple connections share the performance hit of GC Superserver s default behaviour for GC is now to combine cooperative and background modes The new default behaviour generally guarantees better overall performance as the garbage collec tion is performed online curtailing the growth of version chains under high load It means that some queries may be slower to start to return data if the volume of old record ver sions in the affected tables is especially high ODS10 and lower databases having ineffective garbage collection on indices will be particularly prone to this problem The GCPolicy parameter in firebird conf allows the former behaviour to be reinstated if you have databases exhibiting this problem 102 Known Compatibility Issues Firebird API Note the following changes affecting the API isc_interprete is deprecated isc_interprete is deprecated as dangerous Use fb_interpret instead Events callback routine declaration corrected The new prototype for isc callback reflects the actual callback signature Formerly it was typedef void isc callback 0 ISC STATUS isc que eventsq ISC STATUS isc db handle ISC LONG short char isc callback void In the Firebird 2 0 API it is typedef void ISC EVENT CALLBACK void I
169. ut our previous node already contained the F so due to prefix compression this one is ignored and only U is stored NULL state The data that needs to be stored is determined in the procedure compress in btr cpp For ASC ascending indexes no data will be stored key is zero length This will automatically put them as first entry in the index and thus correct order For single field index node length and prefix is Zero DESC descending indexes will store a single byte with the value OxFF 255 To distinguish between a value empty string can be 255 and an NULL state we insert a byte of OxFE 254 at the front of the data This is only done for values that begin with OxFF 255 or OxFE 254 so we keep the right order Figure 8 4 Examples prefix length stored data real value state 0 0 NULL 0 0 NULL 0 1 x65 A A 1 1 x65 A AA xFE xFE b x4A J OxFE Ox4A 0 2 1 1 xFF y OxFF 0 1 xFF NULL 1 0 xFF NULL END LEVEL Enhancements to Indexing 0 0 NULL NULL NULL o 4g X01 1 x70 F x73 1 x82 R x69 E NULL NULL x01 1 x66 B x73 I x82 R x68 D FIREBIRD Q 4g 02 2 x70 F x73 1 x82 R x69 E NULL FIREBIRD x02 2 x66 B x73 I x82 R x68 D NULL o 4g 03 3 x70 F x73 1 x82 R x69 E FIREBIRD NULL x03 3 x66 B x73 I x82 R x68 D NULL 4 g X00 0 x00 x02 2 x65 A x000 ci a p x00 0 x00 0 x01 1 x66 B A xFC xB9 xB6 xFF xFF xFD xBE 0 12 xXFFxFF xFF xFE xBD iei xAD xBA xFC xBD xB6 xAD
170. vel list and posting the best possible bug description you can Firebird devel is not for discussing bugs in your software If you are a novice with Firebird and need help with any issue you can subscribe to the firebird support list and email your questions to firebird support yahoogroups com Tip You can subscribe to this and numerous other Firebird related support forums from the Lists and Newsgroups page at the Firebird website General Notes Documentation A full integrated manual for Firebird 2 0 and preceding releases is well on the way but it s not quite with us yet Meanwhile there is plenty of documentation around for Firebird if you know where to look Study the Novices Guide and Knowledgebase pages at the Firebird website for links to papers and other documents to read on line and or download Don t overlook the materials in the bin directory of your Firebird installation In particular make use of the Firebird 2 0 Quick Start Guide to help you get started The Firebird Docs Project The Firebird Project has an integral user documentation project a team of volunteers who are writing editing and adapting user manuals white papers and HowTos At the time of this release the hard working coordinator of the Docs project is Paul Vinkenoog An index of available documents can be found on the project s web page along with news about pro gress Published docs currently include the essential Quick
171. xBB 3 17 xFDxFFxFFxFFxFFxFExFF FIREBIRD NULL xFF xFF xFF xFF xFF xFF xFF xFD xB9 xB6 1 19 xADxBAxFDxBDxB6xADxBB Nuh FIREBIRD XFE xFF xFF xFF xFF 5 44 XFFXFFXFFxFFXxFExB9xB6 NULL NULL xAD xBA xFE xBD xB6 xAD xBB FIREBIRD 11 4 xFF xFF xFF xFF NULL NULL NULL END LEVEL Chapter 9 Optimizations Improved PLAN Clause D Yemanov A PLAN clause optionally allows you to provide your own instructions to the engine and have it ig nore the plan supplied by the optimizer Firebird 2 enhancements allow you to specify more possible paths for the engine For example PLAN A ORDER IDX1 INDEX IDX2 IDX3 For more details please refer to the topic in the DML section Query Plans Improvements in Hand ling User specified Query Plans Optimizer Improvements This chapter represents a collection of changes done in Firebird 2 0 to optimize many aspects of per formance For All Databases The following changes affect all databases Some General Improvements O Loa D Yemanov Much faster algorithms to process the dirty pages tree Firebird 2 0 offers a more efficient processing of the list of modified pages a k a the dirty pages tree It affects all kinds of batch data modifications performed in a single transaction and elimin ates the known issues with performance getting slower when using a buffer cache of gt 10K pages This change also improves the overall performance of data modifications Increase
172. xing InterBase database file names The issue is described in more detail in Other Win32 Issues at the end of the Windows installation notes Other Pre installation Issues Installing Multiple Servers One of the design goals since Firebird 1 5 has been to prepare the way for running multiple Firebird servers simultaneously on the same host machine Firebird 2 0 does support this although it is not well documented and very much requires intervention from a skilled user A future sub release of Firebird 2 0 will make this process far less complicated to install and manage If you are experienced with Firebird and have a requirement to run multiple Firebird servers side by side please consult the Firebird 1 5 3 release notes for details of how to achieve it Installation of Microsoft system libraries The problems associated with installing different versions of Microsoft system libraries are so notori ous that it has acquired the name DLL Hell From the release of Windows 2000 onwards Microsoft have made it almost impossible to upgrade system dll s To resolve this Microsoft now recommends that each application installs local copies of any system libraries that are required Firebird 1 5 follows this practice and places the required libraries in the bin directory along with the server Installation of fbclient dll Since Firebird 1 5 gds32 dll is not the native name of the client library It is now called fbclient dll Given
173. xpression used in the predicate must match exactly the expression used in the index de claration in order to allow the engine to choose an indexed access path The given index will not be available for any retrieval or sorting operation if the expressions do not match 2 Expression indices have exactly the same features and limitations as regular indices except that by definition they cannot be composite multi segment Changes to Null keys handling V Horsun A Brinkman Null keys are now bypassed for uniqueness checks V Horsun If a new key is inserted into a unique index the engine skips all NULL keys before starting to check for key duplication It means a performance benefit as from v 1 5 on NULLs have not been considered as duplicates NULLs are ignored during the index scan when it makes sense to ignore them A Brinkman Prevously NULL keys were always scanned for all predicates Starting with v 2 0 NULL keys are usually skipped before the scan begins thus allowing faster index scans Note The predicates IS NULL and IS NOT DISTINCT FROM still require scanning of NULL keys and they disable the aforementioned optimization Improved Index Compression A Brinkman A full reworking of the index compression algorithm has made a manifold improvement in the per formance of many queries Selectivity Maintenance per Segment D Yemanov A Brinkman Index selectivities are now stored on a per se

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