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Re: Oracle processes using more than 350Mb memory

From: Shivaswamy Raghunath <>
Date: Fri, 13 Oct 2006 09:01:19 -0400
Message-ID: <>

Hi Vijay,

Is the memory still an issue?

Like Mark mentions, please tell us about the OS. Also, again as Mark says, TOP may be all that suited in this case. Anyway, which column of top you are referring to? Are you able to identify the PGAs used by each of the Oracle session?


On 10/12/06, Bobak, Mark <> wrote:
> You didn't mention what platform / OS you're running (always include that
> info!), but based on your mention of 'top', I'm going to guess it's a flavor
> of unix.
> top doesn't accurately represent the size of an Oracle process, cause all
> oracle processes attach to the SGA's shared memory segments, so, they all
> report a larger amount of memory than that individual process is actually
> consuming. If you have a 1/2 GB SGA, and there are 100 oracle processes,
> using reporting tools like top, you may think Oracle processes are consuming
> 51200MB of RAM. On a box w/ 2GB of RAM, clearly, that can't be right.
> That's cause that 512MB of RAM dedicated to the SGA got counted in every
> oracle process's memory map, but it's shared, it's only in memory once.
> On Solaris (and probably other flavors of unix), try:
> pmap -x <pid of oracle process>
> Look at the pmap output, and discard the line(s) where the shared memory
> is counted. That will give you a better idea of per process memory usage.
> Hope that helps,
> -Mark
> PS There was very recently a lengthy thread about the inadequacies of
> memory accounting under Linux. If you're on Linux, you may want to search
> the archives for that thread.
> ***--*
> *Mark J. Bobak*
> *Senior Oracle Architect*
> ***P****ro****Q****uest Information & Learning*
> There is nothing so useless as doing efficiently that which shouldn't be
> done at all. –Peter F. Drucker, 1909-2005
> ------------------------------
> *From:* [mailto:
>] *On Behalf Of *Vijaya Vardhineni
> *Sent:* Thursday, October 12, 2006 7:41 PM
> *To:*
> *Subject:* Oracle processes using more than 350Mb memory
> Hi
> On one of our database servers, we just have only one Oracle with the following memory parameters.
> pga_aggregate_target=104857600
> shared_pool_size = 117440512
> db_cache_size=251658240
> large_pool_size=16777216
> java_pool_size=67108864
> Top shows that some of the oracle processes are taking more than 350Mb
> memory. These are not the back ground processes associated with the
> instance. Database server has only 2Gb RAM. Can someone explain me what
> could be causing such a high memory usage.
> Regards
> Vijay

Received on Fri Oct 13 2006 - 08:01:19 CDT

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