DB2 - Problembeschreibung
Problem IC98202 | Status: Geschlossen |
OUTER JOIN QUERIES WITH COMPLEX OPERANDS MAY EXPERIENCE POOR PERFORMANCE | |
Produkt: | |
DB2 FOR LUW / DB2FORLUW / A50 - DB2 | |
Problembeschreibung: | |
Outer join queries where the operand producing NULL values for unpaired rows may experience poor performance. - The operand producing the NULL values is a sub-select referencing several tables, views or nested-subselects and produces a very large result set. - The operand driving the outer join references at least two tables and of those tables, one table is small and filters the data but is not directly referenced in a join predicate with the NULL producing operand. In this situation the small table providing the filtering may not be used to effectively filter the NULL producing operand. For example SELECT ... FROM (SELECT T1.C3 FROM T1 INNER JOIN T2 ON T1.C1=T2.C1) as A LEFT JOIN (SELECT T3.C3 FROM T3 INNER JOIN T4 ON T3.C2=T4.C2) as B ON A.C3=B.C3; If table T1, T3 and T4 are very large tables and T2 is a very small table then table T2 may not be used to provide early filtering of the result. | |
Problem-Zusammenfassung: | |
**************************************************************** * USERS AFFECTED: * * ALL * **************************************************************** * PROBLEM DESCRIPTION: * * See Error Description * **************************************************************** * RECOMMENDATION: * * Update to 10.5.0.3 * **************************************************************** | |
Local-Fix: | |
N/A | |
verfügbare FixPacks: | |
DB2 Version 10.5 Fix Pack 3 for Linux, UNIX, and Windows | |
Lösung | |
Problem Fixed In 10.5.0.3 | |
Workaround | |
keiner bekannt / siehe Local-Fix | |
Weitere Daten | |
Datum - Problem gemeldet : Datum - Problem geschlossen : Datum - der letzten Änderung: | 09.12.2013 07.03.2014 07.03.2014 |
Problem behoben ab folgender Versionen (IBM BugInfos) | |
Problem behoben lt. FixList in der Version | |
10.5.0.3 | |
10.5.0.3 |