[
http://tracker.firebirdsql.org/browse/CORE-2709?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Dmitry Yemanov reopened CORE-2709:
----------------------------------
Fix Version/s: (was: 3.0 Alpha 1)
Rolled back from FB3 as well, due to the found regressions. Other solutions are
being investigated.
> Many indexed reads in a compound index with NULLs
> -------------------------------------------------
>
> Key: CORE-2709
> URL: http://tracker.firebirdsql.org/browse/CORE-2709
> Project: Firebird Core
> Issue Type: Bug
> Components: Engine
> Affects Versions: 2.1.0, 2.0.4, 2.1.1, 2.0.5, 2.1.2, 2.5 Beta 2, 2.1.3,
> 3.0 Initial, 2.0.6, 2.5.0, 2.1.4
> Environment: Firebird-2.5.0.25731-0_Win32
> Reporter: Alex Bekhtin
> Assignee: Dmitry Yemanov
>
> CREATE TABLE TEST_TABLE (
> ID1 INTEGER,
> ID2 INTEGER,
> ID3 INTEGER
> );
> COMMIT;
> INSERT INTO TEST_TABLE (ID1, ID2, ID3) VALUES (1, 1, NULL);
> INSERT INTO TEST_TABLE (ID1, ID2, ID3) VALUES (1, 2, NULL);
> INSERT INTO TEST_TABLE (ID1, ID2, ID3) VALUES (1, 3, NULL);
> INSERT INTO TEST_TABLE (ID1, ID2, ID3) VALUES (2, 1, NULL);
> INSERT INTO TEST_TABLE (ID1, ID2, ID3) VALUES (2, 2, NULL);
> INSERT INTO TEST_TABLE (ID1, ID2, ID3) VALUES (2, 3, NULL);
> COMMIT;
> CREATE INDEX TEST_TABLE_IDX1 ON TEST_TABLE (ID1, ID2);
> COMMIT;
> select * from test_table where ID1 = 1 and ID2 = 2
> -- one indexed read
> select * from test_table where ID1 = 1 and ID2 IS NULL
> -- zero indexed read
> DROP INDEX TEST_TABLE_IDX1;
> CREATE INDEX TEST_TABLE_IDX1 ON TEST_TABLE (ID1,ID2,ID3);
> select * from test_table where ID1 = 1 and ID2 = 2
> -- one indexed read again
> select * from test_table where ID1 = 1 and ID2 IS NULL
> -- 3(!!!) indexed reads
--
This message is automatically generated by JIRA.
-
If you think it was sent incorrectly contact one of the administrators:
http://tracker.firebirdsql.org/secure/Administrators.jspa
-
For more information on JIRA, see: http://www.atlassian.com/software/jira
------------------------------------------------------------------------------
Introducing AppDynamics Lite, a free troubleshooting tool for Java/.NET
Get 100% visibility into your production application - at no cost.
Code-level diagnostics for performance bottlenecks with <2% overhead
Download for free and get started troubleshooting in minutes.
http://p.sf.net/sfu/appdyn_d2d_ap1
Firebird-Devel mailing list, web interface at
https://lists.sourceforge.net/lists/listinfo/firebird-devel
