That's how Linux manages memory and the expected behaviour
Charles Hooper wrote:
> 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 Mon Nov 13 2006 - 20:12:30 CST
