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Problem IC84497
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Status: Closed |
OPTIMIZER'S ESTIMATED CARDINALITY INCORRECTLY DROPS AT TQ OPERATOR WHEN QUERY CONTAINS NODENUMBER PREDICATE |
| product: |
DB2 FOR LUW / DB2FORLUW / A10 - DB2 |
| Problem description: |
If a query contains a predicate on NODENUMBER which restricts
to a single node (such as NODENUMBER(T1.C1) = <const>), the
optimizer may incorrectly reduce the estimated cardinality at
certain TQ operators in the access plan. This can potentially
lead to a suboptimal plan choice. |
| Problem Summary: |
****************************************************************
* USERS AFFECTED: *
* Any DPF users with nodenumber predicates *
****************************************************************
* PROBLEM DESCRIPTION: *
* See Error Description *
****************************************************************
* RECOMMENDATION: *
* Upgrade to DB2 Version 10.1 Fixpack 1 or later *
**************************************************************** |
| Local Fix: |
If the TQ cardinality drops at the TQ of a base table,
replicating the base table may correct the cardinality, but
this depends on the optimizer choosing to use the replicated
table based on cost. |
| available fix packs: |
DB2 Version 10.1 Fix Pack 1 for Linux, UNIX, and Windows
DB2 Version 10.1 Fix Pack 2 for Linux, UNIX, and Windows
DB2 Version 10.1 Fix Pack 3 for Linux, UNIX, and Windows
DB2 Version 10.1 Fix Pack 4 for Linux, UNIX, and Windows
DB2 Version 10.1 Fix Pack 3a for Linux, UNIX, and Windows
DB2 Version 10.1 Fix Pack 6 for Linux, UNIX, and Windows
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| Solution |
Problem first fixed in DB2 Version 10.1 Fixpack 1 |
| Workaround |
not known / see Local fix |
| Timestamps |
Date - problem reported :
Date - problem closed :
Date - last modified :
| 14.06.2012
03.12.2012
03.12.2012 |
| Problem solved at the following versions (IBM BugInfos) |
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| Problem solved according to the fixlist(s) of the following version(s) |
| 10.1.0.1
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 |
| 10.5.0.1
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