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RE: Combined SGA size and Total Memory

From: Thomas Biju <>
Date: Wed, 23 Jun 2004 19:15:03 -0500
Message-ID: <>

I apologize for the garbage email... One more try. Yes, I was the same person who sent this type of email couple of weeks back too... (Need to learn windows I guess)

-----Original Message-----

From: Thomas Biju
Sent: Wednesday, June 23, 2004 7:04 PM
To:; '' Subject: RE: Combined SGA size and Total Memory

No, I'm not talking about increasing the size of SGA simply because we have memory. The reason for the question was basically different. We typically create new databases on the same HP or Sun server which currently host anywhere from 6 to 23 databases... At what point should we alert the management for a memory upgrade? My point was there should not be any rule of thumb such as SGA should be less than 30% of total RAM, more memory requirement should be based on the load on the server.... Thanks,

-----Original Message-----

From: Graeme Farmer [] Sent: Wed 6/23/2004 6:52 PM
To: ''
Subject: RE: Combined SGA size and Total Memory

I would have thought that the SGA should be as big as it needs to be and no bigger!!

Needlessly allocating extra memory to the SGA just because you have can make Oracle work harder as it has more memory to manage. Buffer chain lengths will increase and scanning and cache chains latch contention has the potential to increase on active systems.

The size of the SGA should also depend on other processes on the system and their usage (including Oracle processes that perhaps require a large sort buffer).


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Received on Wed Jun 23 2004 - 19:12:43 CDT

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