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Problem IC95335
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Status: Geschlossen |
PERFORMANCE DEGRADATION MIGHT BE NOTICED WITH NOT EXISTS SUBQUERY WITH MULTIPLE TABLES. |
| Produkt: |
DB2 FOR LUW / DB2FORLUW / A50 - DB2 |
| Problembeschreibung: |
Under some scenarios, DB2 might choose a suboptimal plan if the
following conditions are true:
1. The query has a not exists subquery
2. The subquery contains 2 or more base tables
3. The correlated join predicate in the subquery has an index on
the join column. |
| Problem-Zusammenfassung: |
Under some scenarios, DB2 might choose a suboptimal plan if the
following conditions are true:
1. The query has a not exists subquery
2. The subquery contains 2 or more base tables
3. The correlated join predicate in the subquery has an index on
the join column. |
| Local-Fix: |
Disable AntiJoin by either :
1> db2set DB2_ANTIJOIN=NO -im
2> set up an optimization guideline to disable the antijoin for
this specific query only. |
| verfügbare FixPacks: |
DB2 Version 10.5 Fix Pack 3 for Linux, UNIX, and Windows
DB2 Version 10.5 Fix Pack 3a for Linux, UNIX, and Windows
DB2 Cancun Release 10.5.0.4 (also known as Fix Pack 4) for Linux, UNIX, and Windows
DB2 Version 10.5 Fix Pack 9 for Linux, UNIX, and Windows
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| Lösung |
Disable AntiJoin by either :
1> db2set DB2_ANTIJOIN=NO -im
2> set up an optimization guideline to disable the antijoin for
this specific query only. |
| Workaround |
keiner bekannt / siehe Local-Fix |
| Weitere Daten |
Datum - Problem gemeldet :
Datum - Problem geschlossen :
Datum - der letzten Änderung:
| 27.08.2013
09.04.2014
09.04.2014 |
| Problem behoben ab folgender Versionen (IBM BugInfos) |
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| Problem behoben lt. FixList in der Version |
| 10.5.0.3
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 |
| 10.5.0.3
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| 10.5.0.4
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