DB2 FOR LUW / DB2FORLUW / 950 - DB2

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

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* USERS AFFECTED:                                              * 
* All users                                                    * 
**************************************************************** 
* PROBLEM DESCRIPTION:                                         * 
* See Error Description                                        * 
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* RECOMMENDATION:                                              * 
* Upgrade to DB2 version 9.5.0.10.                             * 
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The problem is first fixed in DB2 version 9.5.0.10.

not known / see Local fix

Date  - problem reported    :
Date  - problem closed      :
Date  - last modified       :

14.05.2012
22.08.2012
22.08.2012

9.5.0.10