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Problem IC96632
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Status: Geschlossen |
POOR QUERY PERFORMANCE IF JOIN PREDICATE APPLIED TO THE FIRST AND LAST COLUMNS OF AN INDEX WITH INTERMEDIATE LOCAL PREDICATES |
| Produkt: |
DB2 FOR LUW / DB2FORLUW / A50 - DB2 |
| Problembeschreibung: |
Query performance may be poor when the query contains at least
three (3) tables joined together using INNER or OUTER joins and
there are at least 2 equal join predicates and at least two
local equality predicate.
The last table in the join sequence must have multicolumn
index covering the columns involved in the predicates. The
equality join predicates must be applicable on the first and
last columns of the index with the local eer quality predicate
applicable on the intermediate columns of the index.
Under these conditions the optimizer may incorrect calculate
the cost of the joins leading to a poorly performing plan. |
| Problem-Zusammenfassung: |
****************************************************************
* USERS AFFECTED: *
* All *
****************************************************************
* PROBLEM DESCRIPTION: *
* See Error Description *
****************************************************************
* RECOMMENDATION: *
* Upgrade to DB2 version 10.5 fixpack 3 *
**************************************************************** |
| Local-Fix: |
Use an optimization profile to obtain a better join order
or
Change the index definition so that the join predicate are
applicable to either the leading or trailing columns of the
index without any intermediate local equality predicates. |
| 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
|
| Lösung |
Problem was first fixed in DB2 version 10.5 fixpack 3 |
| Workaround |
keiner bekannt / siehe Local-Fix |
| Weitere Daten |
Datum - Problem gemeldet :
Datum - Problem geschlossen :
Datum - der letzten Änderung:
| 04.10.2013
27.02.2014
27.02.2014 |
| 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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