Re: SGA size

gautam_at_saturn.bwc.org (Gautam Das) wrote:
>Is it better to have a small SGA (say 16megs) and large shared
>memory allocated (say SHMMAX=128Megs) on a Solaris 2.5 system,
>so Oracle can add several SGA areas as it needs, or a single very
>large SGA

Oracle will only use the SGA that you give it, so make your SGA as big as it needs to be (allowing some free memory for other stuff of course).

Assuming you are using Oracle 7, you should calculate the sga size by first calculating the size of your shared pool (I would say 18Mb is a minimum for a large database), then the size of the buffer cache (something like 3000 block buffers for a large database)

The above figures are of course arbitary, and very dependent on your database and application software.

There are plenty of ways of getting information about your sga, and checking that the sizes are correct, I recommend you get a tuning reference book (the O'reilly book is excellent (the one with bees on the cover)). Received on Mon Sep 09 1996 - 00:00:00 CEST