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Problem IC70679
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Status: Geschlossen |
SERVER OPTIONS NEED TO BE ADDED TO ADJUST COST ESTIMATION FOR FETCHING DATA FROM REMOTE SERVER IN CERTAIN ENVIRONMENT |
| Produkt: |
DB2 FOR LUW / DB2FORLUW / 950 - DB2 |
| Problembeschreibung: |
In certain environment, cost for fetching massive rows from
remote server is over-cost, while execution of a remote
statement multi-times is under-cost. As a result, IFS chooses a
NLJN which fetches remote data for multi-times, instead of
choosing the HSJN which fetches all data of a remote table at
one time, and the performance could be bad with the NLJN. |
| Problem-Zusammenfassung: |
Problem Description:
SERVER OPTIONS NEED TO BE ADDED TO ADJUST COST ESTIMATION FOR
FETCHING DATA FROM REMOTE SERVER IN CERTAIN ENVIRONMENT
Problem Summary:
In certain environment, cost for fetching massive rows from
remote server is over-cost, while execution of a remote
statement multi-times is under-cost. As a result, IFS chooses a
NLJN which fetches remote data for multi-times, instead of
choosing the HSJN which fetches all data of a remote table at
one time, and the performance could be bad with the NLJN. |
| Local-Fix: |
Use plan hints, explicit selectivity, stats views to force the
HSJN plan. |
| verfügbare FixPacks: |
DB2 Version 9.5 Fix Pack 7 for Linux, UNIX, and Windows
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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| Lösung |
Problem is first fixed in Version 9.5 Fixpack 7 |
| Workaround |
Use plan hints, explicit selectivity, stats views to force the
HSJN plan. |
| Weitere Daten |
Datum - Problem gemeldet :
Datum - Problem geschlossen :
Datum - der letzten Änderung:
| 20.08.2010
11.02.2011
11.02.2011 |
| Problem behoben ab folgender Versionen (IBM BugInfos) |
9.5.FP7
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| Problem behoben lt. FixList in der Version |
| 9.1.0.7
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 |
| 9.5.0.7
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