DB2 FOR LUW / DB2FORLUW / A50 - DB2

When a sort operation is aborted, it is assumed that a larger 
sort configuration would have avoided the circumstances 
triggering the abort.  The information used by STMM is 
intentionally heavily biased towards increasing the sort 
configuration.  While this is a reasonable approach when an 
out-of-memory error is the reason for a sort operation not 
completing, this is not a good assumption for interrupted 
queries - they could be long-running and interrupted by a 
user/application for a variety of reasons. 
 
An isolated interrupted query that leads to a single errant 
tuning increase of sort (sheapthres_shr) should have negligible 
overall impact on a system's performance.  However, if 
interrupted queries are continuous/frequent, the sort 
configuration may be tuned excessively high to the detriment of 
overall performance.  The situation may become severe and 
prolonged due to bufferpools being decreased to unacceptably low 
sizes. 
 
Interrupted queries can be identified in the db2diag.log by the 
following message/code: 
 
FUNCTION: DB2 UDB, runtime interpreter, sqlrisrt, probe:50 
DATA #2 : Hexdump, 4 bytes 
0x00002AE4D9FFD48C : 0300 0480 
.... 
 
Or on big-endian architectures : 8004 0003

**************************************************************** 
* USERS AFFECTED:                                              * 
* ALL                                                          * 
**************************************************************** 
* PROBLEM DESCRIPTION:                                         * 
* See Error Description                                        * 
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* RECOMMENDATION:                                              * 
* Upgrade to Db2 10.5 Fix Pack 9 or higher                     * 
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manually adjust the sort configuration to correct the 
configuration : 
  db2 connect to <database> 
  db2 update db cfg for <database> using sheapthres_shr <value> 
automatic 
 
If the interrupts are frequent and cannot be avoided, it may be 
necessary to remove sort from automatic/STMM tuning until the 
fix for this APAR is applied.

First fixed in Db2 10.5 Fix Pack 9

not known / see Local fix

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

04.05.2017
29.09.2017
29.09.2017

9.0.