RE: Actually PGA allocated > PGA_AGGREGATE_TARGET ?

From: Ric Van Dyke <ric.van.dyke_at_hotsos.com>
Date: Mon, 10 Aug 2009 13:10:21 -0500
Message-ID: <C970F08BBE1E164AA8063E01502A71CF01514CFB_at_WIN02.hotsos.com>

Key words that help in this is that it's a TARGET not a LIMIT. And as it says it "attempts" to stay below this. It can and will (as in your case) accede this.  

It looks like at one time oracle needed 1.3G and more recently it needed 1.2G but right now is using .9G. From this as a SWAG I'd say you should set PGA_AGGREGATE_TARGET to about 1.2G. The issue is that once you go above the target, I think it's SMON that will get excited about trying to bring the allocated back done. This would cause a little be more activity at the system level. However this is unlikely to be a big deal.  

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Ric Van Dyke

Hotsos Enterprises

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Hotsos Symposium

March 7 - 11, 2010

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From: oracle-l-bounce_at_freelists.org
[mailto:oracle-l-bounce_at_freelists.org] On Behalf Of Jiang, Lu Sent: Monday, August 10, 2009 1:56 PM
To: Oracle-L Freelists
Subject: Actually PGA allocated > PGA_AGGREGATE_TARGET ?  

Hi all,  

The following is my query result against v$pgastat view. PGA_AGGREGATE_TARGET is set to 1G. According to Oracle' documentation, Oracle should attempts to keep the amount of private memory below the PGA_AGGREGATE_TARGET specified. But from the following it looks Oracle allocated 1.2G PGA memory, and the maximum PGA allocated is 1.3GB which is far above 1G (PGA_AGGREGATE_TARGET), I am confused. Could anyone share some light on this?  

aggregate PGA target parameter

1,073,741,824.00

bytes

aggregate PGA auto target

85,053,440.00

bytes

global memory bound

107,366,400.00

bytes

total PGA inuse

984,952,832.00

bytes

total PGA allocated

1,259,997,184.00

bytes

maximum PGA allocated

1,347,652,608.00

bytes  

Thanks,

Lu

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Received on Mon Aug 10 2009 - 13:10:21 CDT