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anish wrote:
> My linux box(rhel as 4) where oracle instance is located is showing
> nearly 100 memory utilization (using top command). Changing resource
> limit using 'ulimit' is not showing any significant improvements.How
> can i fix the upper limit of memory utilization.Oracle version is
> 9.2.0.5
>
> Thanks and regards
Memory utilization for Oracle is largely controlled by the settings in the init.ora (pfile) or the spfile, and the number of sessions connecting to the instance. These parameters are visible by selecting from the V$PARAMETER view. A couple of the parameters to be examined: SORT_AREA_SIZE, SORT_AREA_RETAINED_SIZE, SESSION_CACHED_CURSORS, SHARED_POOL_SIZE, LARGE_POOL_SIZE, JAVA_POOL_SIZE, DB_BLOCK_BUFFERS, OPEN_CURSORS, BUFFER_POOL_KEEP, BUFFER_POOL_RECYCLE, DB_nK_CACHE_SIZE, DB_CACHE_SIZE, DB_KEEP_CACHE_SIZE, DB_RECYCLE_CACHE_SIZE, HASH_AREA_SIZE, LOG_BUFFER, OPEN_CURSORS, PGA_AGGREGATE_TARGET, SGA_MAX_SIZE, SGA_TARGET, SHARED_POOL_RESERVED_SIZE, WORKAREA_SIZE_POLICY, etc.
As you can see by the number of parameters listed above, there is no silver bullet solution to lowering memory consumption - every change that you make to the above parameters can have a positive, negative, or no change to the performance of the Oracle instance. Each session consumes a little bit of memory when it connects, and then potentially consumes a lot of memory when the session becomes active. Some of wild swings of memory utilization can be controlled by the use of WORKAREA_SIZE_POLICY = AUTO, and by specifying an upper limit for SGA_MAX_SIZE. Exciting things happen when the Oracle process, at least on the Windows platform, bounce into the upper limit for 32 bit applications - when one more session tries to connect.
If you can, provide the values for the above parameters. Doing so may be enough for someone to provide specific advice.
Charles Hooper
PC Support Specialist (which of course is an alias for Oracle DBA, IT
manager, Sr. programmer, corporate trainer, Sr. hardware technician,
application expert, and the head nerd in the Magic Kingdom)
K&M Machine-Fabricating, Inc.
Received on Fri Nov 10 2006 - 19:07:51 CST