DB2 - Problembeschreibung
| Problem IC94861 | Status: Geschlossen |
MERGE STATEMENT WITH ONLY MATCHED CONDITION AND DISTINCT MIGHT LEAD TO PERFORMANCE DEGRADATION | |
| Produkt: | |
DB2 CONNECT / DB2CONNCT / 970 - DB2 | |
| Problembeschreibung: | |
Some queries might see performance degradation starting DB2
version 970 fix pack 6 if the following conditions are true:
1. The query is a merge statement with only the matched
condition
2. The Source of the merge is a distinct join between two or
more tables, alias
3. (Optional) One of the tables in this join is the same as the
target table
eg. MERGE INTO MYALIAS.TAB1 AS TGT USING <----------- condition
1
(SELECT DISTINCT A.TRN, A.SYS, A.LANG <-----------
condition 2
FROM MYALIAS.TAB2 A, MYALIAS.TAB1 B <-----------
condition 3
WHERE A.TRN = B.TRN AND NULLIF(B.TRN , '') IS NOT NULL
AND A.SYS = B.SYS AND A.LANG = B.LANG) AS STG
ON STG.TRN = TGT.TRN
WHEN MATCHED THEN
UPDATE SET TGT.TRN = STG.TRN; | |
| Problem-Zusammenfassung: | |
**************************************************************** * USERS AFFECTED: * * Users using Merge statement * **************************************************************** * PROBLEM DESCRIPTION: * * See Error Description * **************************************************************** * RECOMMENDATION: * * Upgrade to DB2 V9.7 Fix pack 9 or higher. * **************************************************************** | |
| Local-Fix: | |
| verfügbare FixPacks: | |
DB2 Version 9.7 Fix Pack 9 for Linux, UNIX, and Windows | |
| Lösung | |
Problem fixed in DB2 V9.7 Fix pack 9 and above. | |
| Workaround | |
keiner bekannt / siehe Local-Fix | |
| Bug-Verfolgung | |
Vorgänger : APAR is sysrouted TO one or more of the following: IC95130 Nachfolger : | |
| Weitere Daten | |
Datum - Problem gemeldet : Datum - Problem geschlossen : Datum - der letzten Änderung: | 13.08.2013 18.12.2013 18.12.2013 |
| Problem behoben ab folgender Versionen (IBM BugInfos) | |
9.7.FP9 | |
| Problem behoben lt. FixList in der Version | |
| 9.7.0.9 |
|
| 9.7.0.9 |
|