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Problem IC84204
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Status: Closed |
DB2 MAY NOT PERFORM OPTIMALLY ON LARGE 64-BIT WINDOWS ENVIRONMENTS DUE TO USE OF MEM_TOP_DOWN FLAG |
| product: |
DB2 FOR LUW / DB2FORLUW / A10 - DB2 |
| Problem description: |
DB2 uses the MEM_TOP_DOWN flag for many memory allocations
(VirtualAlloc API) on the Windows platform. The use of this
flag causes memory allocations to take longer as the number of
allocations gets larger. The MEM_TOP_DOWN flag is used
primarily to avoid address space fragmentation in 32-bit
environments, and is not needed with 64-bit, so its use will be
restricted to 32-bit DB2.
The symptom may be particularly noticable when initializing
large bufferpools.
A workaround exists, that is to set the following internal
registry variable:
db2set DB2_MEMALLOCATE_HIGH=NO
The instance must be recycled with db2stop; db2start |
| Problem Summary: |
****************************************************************
* USERS AFFECTED: *
* Large systems running DB2 on the Windows platform *
****************************************************************
* PROBLEM DESCRIPTION: *
* See Error Description *
****************************************************************
* RECOMMENDATION: *
* Use the temporary workaround or upgrade to DB2 Version 10.1 *
* Fix Pack 1. If using the workaround, ensure the setting is *
* removed after upgrading to DB2 Version 10.1 Fix Pack 1 or *
* higher. *
**************************************************************** |
| Local Fix: |
db2set DB2_MEMALLOCATE_HIGH=NO
The instance must be recycled with db2stop; db2start |
| available fix packs: |
DB2 Version 10.1 Fix Pack 1 for Linux, UNIX, and Windows
DB2 Version 10.1 Fix Pack 2 for Linux, UNIX, and Windows
DB2 Version 10.1 Fix Pack 3 for Linux, UNIX, and Windows
DB2 Version 10.1 Fix Pack 4 for Linux, UNIX, and Windows
DB2 Version 10.1 Fix Pack 3a for Linux, UNIX, and Windows
DB2 Version 10.1 Fix Pack 6 for Linux, UNIX, and Windows
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| Solution |
First fixed in DB2 Version 10.1 Fix pack 1 |
| Workaround |
See Local Fix |
| Timestamps |
Date - problem reported :
Date - problem closed :
Date - last modified :
| 13.06.2012
02.11.2012
02.11.2012 |
| Problem solved at the following versions (IBM BugInfos) |
|
| Problem solved according to the fixlist(s) of the following version(s) |
| 10.1.0.1
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 |
| 10.5.0.1
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