DB2 - Problembeschreibung
Problem IC83426 | Status: Geschlossen |
INDEX SCAN MAY RETURN WRONG RESULTS | |
Produkt: | |
DB2 FOR LUW / DB2FORLUW / 950 - DB2 | |
Problembeschreibung: | |
There is a very small timing hole that could result in an index scan not returning all of the qualifying rows. The error can occur in one of two scenarios: 1. To hit the problem in scenario #1 all of the following must be true: - the index is defined using the MINPCTUSED keyword - a DELETE statement is executed such that the delete: * has exclusive access to the table either obtained via the LOCK TABLE <tableName> IN EXCLUSIVE MODE statement or via lock escalation * merges the right-most leaf page (P1) of a branch of the index tree (where a branch is an intermediate node in the index and all of the leaf nodes underneath it) with the left-most leaf page (P2) of the next two-level branch of the index tree, deleting leaf page P1 in the process * is rolled back either explicitly via the ROLLBACK statement or because an error was hit - a SELECT statement is executed such that the SELECT: * uses the UR (Unrepeatable Read) isolation level * uses an index scan * uses a start key that belongs in leaf page P1 (see above) before the page merge/deletion occurs * starts probing the index while the page merge/deletion is in progress 2. To hit the problem in scenario #2 all of the following must be true: - a REORG INDEXES command is executed with the CLEANUP ONLY ALL option OR a REORG TABLE command is executed with the INPLACE option such that the REORG INDEXES/TABLE command: * merges the right-most leaf page (P1) of a branch of the index tree with the left-most leaf page (P2) of the next branch of the index tree, deleting leaf page P1 in the process * hits a log-full error when writing the last log record that is part of the page merge/deletion operation - a SELECT statement is executed such that the SELECT: * uses an index scan * uses a start key that belongs in leaf page P1 (see above) before the page merge/deletion occurs * starts probing the index while the page merge/deletion is in progress | |
Problem-Zusammenfassung: | |
**************************************************************** * USERS AFFECTED: * * All users * **************************************************************** * PROBLEM DESCRIPTION: * * See Error Description * **************************************************************** * RECOMMENDATION: * * Upgrade to DB2 version 9.5.0.10. * **************************************************************** | |
Local-Fix: | |
Lösung | |
The problem is first fixed in DB2 version 9.5.0.10. | |
Workaround | |
keiner bekannt / siehe Local-Fix | |
Weitere Daten | |
Datum - Problem gemeldet : Datum - Problem geschlossen : Datum - der letzten Änderung: | 14.05.2012 22.08.2012 22.08.2012 |
Problem behoben ab folgender Versionen (IBM BugInfos) | |
9.5.0.10 | |
Problem behoben lt. FixList in der Version | |
9.5.0.10 |