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Problem IC84502
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Status: Geschlossen |
ESTIMATED CARDINALITY OF UNNEST FUNCTION FOR ARRAY DATATYPE IS NOT USED DURING QUERY PLANNING |
| Produkt: |
DB2 FOR LUW / DB2FORLUW / A10 - DB2 |
| Problembeschreibung: |
The DB2 optimizer uses the maximum cardinality of an array
during plan generation. In many cases the maximum cardinality is
not a good indicator of the real array size, especially when
arrays are used in stored procedures or packages. As a result,
queries that use the UNNEST function with an array as input may
have poor plans due to the high maximum array cardinality. |
| Problem-Zusammenfassung: |
****************************************************************
* USERS AFFECTED: *
* All users on DB2 v10 GA *
****************************************************************
* PROBLEM DESCRIPTION: *
* See Error Description *
****************************************************************
* RECOMMENDATION: *
* Upgrade to DB2 v10 FP1 *
**************************************************************** |
| Local-Fix: |
As a workaround, the user may specify an estimated cardinality
for the array by updating the statistics of the array cast
function in SYSSTAT.ROUTINES table:
db2 "update sysstat.routines set
cardinality=<cardinality_of_array> where
routineschema='<schema_name_of_array>' and
routinename='<array_name>'"
Dynamic statements will use the new cardinality at the next
compile.
Static packages will need to be rebound to use the new
cardinality. |
| verfügbare FixPacks: |
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
|
| Lösung |
First Fixed DB2 v10 FP1 |
| Workaround |
keiner bekannt / siehe Local-Fix |
| Weitere Daten |
Datum - Problem gemeldet :
Datum - Problem geschlossen :
Datum - der letzten Änderung:
| 14.06.2012
01.11.2012
01.11.2012 |
| Problem behoben ab folgender Versionen (IBM BugInfos) |
|
| Problem behoben lt. FixList in der Version |
| 10.1.0.1
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 |
| 10.5.0.1
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