|
Problem IT21211
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Status: Closed |
SLOW DATABASE ACTIVATION, CREATE/ALTER BUFFERPOOL, LOAD OPERATIONS ON LARGE WINDOWS SYSTEMS |
| product: |
DB2 FOR LUW / DB2FORLUW / B10 - DB2 |
| Problem description: |
On Windows, allocating memory may be
significantly slower for databases with larger memory footprints
( many GBs ). Because DB2's memory allocations on Windows are
typically small and incremental, coalesce checks end up being
performed on a very large number of OS allocations. Activities
which are intense in terms of allocating memory (such as
bufferpool activation, creation, or increase, or initializing
LOAD operations), may suffer some degradation as a result
The call stack will contain the following :
SMemSet::checkRecommitable
SMemSet::recommitChunksUntilTargetReached
SMemSet::getChunksFromTree
SMemSet::getContiguousChunks
SMemBasePool::getNewChunkSubgroup |
| Problem Summary: |
****************************************************************
* USERS AFFECTED: *
* Larger Windows systems *
****************************************************************
* PROBLEM DESCRIPTION: *
* See Error Description *
****************************************************************
* RECOMMENDATION: *
* Upgrade to DB2 Version 11.1 Mod 3 Fix Pack 3 *
**************************************************************** |
| Local Fix: |
Consider using
db2set DB2MEMDISCLAIM=NO
followed by db2stop; db2start, which avoids the need for any
coalesce check.
Note that DB2MEMDISCLAIM=NO disables STMM-tuning of
database_memory, though STMM will still tune the main consumers
(bufferpools, locklist, package cache, shared sort) inside the
existing database_memory size. |
| available fix packs: |
Db2 Version 11.1 Mod 3 Fix Pack 3 for Linux, UNIX, and Windows
Db2 Version 11.1 Mod3 Fix Pack3 iFix001 for Linux, UNIX, and Windows
Db2 Version 11.1 Mod3 Fix Pack3 iFix002 for Linux, UNIX, and Windows
|
| Solution |
Problem first fixed in DB2 Version 11.1 Mod 3 Fix pack 3 |
| Workaround |
see Local Fix |
| Timestamps |
Date - problem reported :
Date - problem closed :
Date - last modified :
| 27.06.2017
15.03.2018
15.03.2018 |
| Problem solved at the following versions (IBM BugInfos) |
|
| Problem solved according to the fixlist(s) of the following version(s) |
