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

Hi Zhu Chao,

There's one material called *SQL Memory Management in Oracle9i, *wroted by Benoît Dageville & Mohamed Zait, it describes how Oracle manage PGA. You may refere to it.

2008/10/7 Zhu,Chao <zhuchao_at_gmail.com>

> 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.
>
> --
> Regards
> Zhu Chao
> www.cnoug.org
>
>

-- 
Regards,
Yaping Chen

http://yaping123.wordpress.com
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