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Problem IC75107
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Status: Closed |
QUERY RETURNS INCORRECT RESULT WHEN INTRA-PARTITION PARALLELISM IS USED |
| product: |
DB2 FOR LUW / DB2FORLUW / 950 - DB2 |
| Problem description: |
A query that used to work fine in V9.1 returns incorrect result
in V9.7. For example:
SELECT * FROM myschema.tbl1
WHERE C1 = 'X'
AND C2 = 'Y'
AND C3 IN ('A', 'B', 'C', 'D', 'E', 'F', 'G', 'H' )
AND C4 = 'V'
AND '2010-01-01' BETWEEN C5 AND C6
AND C7 = 'Z'
AND C8 = '0'
FETCH FIRST 1 ROWS ONLY
The query fails to return any rows even though two rows satisfy
the predicate criteria. If the "fetch first" option is removed,
or "fetch first 2 rows only" is used, the query returns two rows
as expected.
The problem occurs when the following conditions are true:
- Intra-partition parallelism is on
- Query degree is greater than 1
- Index scan is used
- Runstats has been performed against the table and indexes |
| Problem Summary: |
Fix delivered in V9.5 Fixpack 5. |
| Local Fix: |
Disable intra-partition parallelism (may affect performance of
other queries) |
| available fix packs: |
DB2 Version 9.5 Fix Pack 8 for Linux, UNIX, and Windows
DB2 Version 9.5 Fix Pack 9 for Linux, UNIX, and Windows
DB2 Version 9.5 Fix Pack 10 for Linux, UNIX, and Windows
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| Solution |
Fix delivered in V9.5 Fixpack 5. |
| Workaround |
not known / see Local fix |
| Timestamps |
Date - problem reported :
Date - problem closed :
Date - last modified :
| 22.03.2011
05.07.2011
05.07.2011 |
| Problem solved at the following versions (IBM BugInfos) |
9.5.FP5
|
| Problem solved according to the fixlist(s) of the following version(s) |
| 9.5.0.8
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