DB2 - Problembeschreibung
Problem IC63995 | Status: Geschlossen |
VERY SLOW QUERY DUE TO CORRELATED HSJN ON THE INNER OF NLJN | |
Produkt: | |
DB2 FOR LUW / DB2FORLUW / 970 - DB2 | |
Problembeschreibung: | |
Query runs very slow due to a correlated HSJN on the inner of a NLJN. Example : 0.306141 NLJOIN ( 16) 1.03309e+07 199966 /--------------+----------\ 5.9579e+07 5.1384e-09 IXSCAN HSJOIN ( 17) ( 18) 310054 78.8668 199957 9.04414 | /---------+----------\ 5.9579e+07 1 INDEX: GRPBY <schema.inx1> ( 27) Q7 35.0439 4.02207 | 2.55873 FETCH ( 28) 35.0435 4.02207 /---+---\ 2.55873 1.52447e+08 IXSCAN TABLE: ( 29) <schema.tab1> 26.1437 Q9 3 | 1.52447e+08 INDEX: <schema.inx2> Q9 Example of optimized part of SQL : (SELECT MIN(Q10.$C0) FROM (SELECT Q9.<col1> FROM <schema.tab1> AS Q9 WHERE (Q9.<col2> = Q7.<col2>)) AS Q10) AS Q11, This is a side effect of another code fix which went in V9.1 FP5 | |
Problem-Zusammenfassung: | |
Users Affected : Any user using V9.1 FP5 and above Problem Summay : Please see the APAR description Problem Solution : This is an under-estimation of the buffer requirement which is fixed by this APAR | |
Local-Fix: | |
Use optimizer guideline similar to : <OPTGUIDELINES><NLJOIN><ACCESS TABID='Q7'/><ACCESS TABID='Q11'/></NLJOIN></OPTGUIDELINES> | |
verfügbare FixPacks: | |
DB2 Version 9.7 Fix Pack 1 for Linux, UNIX, and Windows | |
Lösung | |
This APAR is fixed in V9.7 FixPak1 (CQ defect#wsdbu00548004) | |
Workaround | |
keiner bekannt / siehe Local-Fix | |
Weitere Daten | |
Datum - Problem gemeldet : Datum - Problem geschlossen : Datum - der letzten Änderung: | 22.10.2009 30.12.2009 30.12.2009 |
Problem behoben ab folgender Versionen (IBM BugInfos) | |
9.7. | |
Problem behoben lt. FixList in der Version | |
9.7.0.1 |