DB2 FOR LUW / DB2FORLUW / 950 - DB2

Problem Description: 
============= 
STMM may tune shared sort memory too high when throttling has 
occured as part of trying to satisfy STMM's "Minimum Size" 
calculation. 
The best way to be sure of this symptom is when the "Minimum 
Size" for Shared Sort Heap in the STMM log is more than 1.25 
times the current or peak shared sort memory usage (seen in a 
database snapshot). 
 
For example, below the Minimum Size is 5288250, but the database 
snapshot shows a high water mark of only 3882760.  The Minimum 
Size is more than 1.25 x the high water mark, which is too high, 
and likely caused by this APAR. 
 
***  stmmCostBenefitRecord *** 
Type: SHEAPTHRES_SHR 
PageSize: 4096 
... 
Current Size: 4363267 (this is the current configured size) 
Minimum Size: 5288250 
 
Database Snapshot: 
Total Shared Sort heap allocated           = 3138402 
Shared Sort heap high water mark           = 3882760

**************************************************************** 
* USERS AFFECTED:                                              * 
* DB2 systems with STMM tuning overall sort memory             * 
* (SHEAPTHRES_SHR)                                             * 
**************************************************************** 
* PROBLEM DESCRIPTION:                                         * 
* See Error Description                                        * 
**************************************************************** 
* RECOMMENDATION:                                              * 
* Upgrade to DB2 Version 9.5 Fix Pack 9                        * 
****************************************************************

Use a fixed size for SHEAPTHRES_SHR

DB2 Version 9.5 Fix Pack 9 for Linux, UNIX, and Windows
 DB2 Version 9.5 Fix Pack 10 for Linux, UNIX, and Windows
 

Problem first fixed in DB2 Version 9.5 Fix Pack 9

not known / see Local fix

forerunner  : APAR is sysrouted TO one or more of the following: IC84135 
follow-up : 

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

19.09.2011
12.06.2012
12.06.2012

9.5.FP9