Affects Version/s: 10.5.1.1, 10.5.2.0, 10.5.3.0, 10.6.1.0, 10.6.2.1, 10.7.1.1, 10.8.1.2, 10.8.2.2, 10.8.3.0, 10.9.1.0, 10.10.1.1
Fix Version/s: None
Bug behavior facts:Performance, Seen in production
Issue originally posted here:
Note by Rick Hillegas:
I think it's worth filing a JIRA for this issue. If the defect is shared
by VTIs and table functions then there's a possibility that ordinary
table scans suffer from it too. That would raise the problem's urgency.
Basically some WHERE clause expressions do not get passed through via RestrictedVTI.initScan().
This can have a severe impact on memory/performance.
(I suspect the issue may be related to logic which tries to move AND nodes to the top of the tree...?)
Examples (I have a few more here than in the post above):
These get passed ok in the Restriction object:
- C1>1 AND C2<'d'
- C1>6 OR C2<'d'
- C1>1 AND (C1<6 OR C2<'d')
This one gets passed partially by initScan():
C1>1 AND (C1<6 OR (C2>'e' AND C2<'d')) ===> initScan() passes only: "C1" > 1
These do not get passed at all (initScan() Restriction argument object is null):
- C1>6 OR (C1>1 AND C2<'d')
- C1>6 OR ((C1>1 AND C2<'d') AND C2>'b')
- C1 in ( 1, 4 )
- C1 in ( 1, 4 ) OR C2>'f' – Can Derby resolve in() clauses to a list of '=' conditions ? This would be useful!
My table function is defined as follows:
CREATE FUNCTION TF_TEST1() RETURNS TABLE(C1 INT, C2 VARCHAR(32672)) PARAMETER STYLE DERBY_JDBC_RESULT_SET LANGUAGE JAVA NOT DETERMINISTIC READS SQL DATA EXTERNAL NAME 'core.TestTableFunctions.TF_TEST1'