using pga_aggregate_target to control total memory usage caused by excessive connection.

From: Zhu,Chao <>
Date: Tue, 7 Oct 2008 23:06:58 +0800
Message-ID: <>

hi, everyone,

    I think many people using this parameter instead of very old *_area_size these days and it just works well for most sites;

    We are running into a different problem. With more and more traffic/SQL execution, we are having more and more connections to the database. Excessive session# is leading to excessive total PGA usage; and we have to continuously reduce the SGA to accomedate the increasing PGA size, or convert to MTS (but MTS comes with very high CPU overhead with high connection# too).

    Just wondering whether it is helpful to use this parameter to control the total PGA caused by the excessive connection. This parameter helps make oracle distribute the tunable pga size between processes. But I am not sure how to estimate the tuneable/un-tunable pga size? v$pgastat/sum(v$process.pga_max_size) is showing 5gb - 7gb pga usage but os stats shows around 10gb-15gb pga usage;

    Our platform is solaris 10/oracle 10.2 on Sparc.

   any comment is welcome. thx.

Zhu Chao

Received on Tue Oct 07 2008 - 10:06:58 CDT

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