sga size

[learn]

What is the appropriate SGA size for any production DB. I heard it should be around 45-50% of the total system memory. Is this true?

[jamiek]

yeah, I know the SGA should never take over 50% of the available memory.

[julian]

Originally posted by learn
What is the appropriate SGA size for any production DB. I heard it should be around 45-50% of the total system memory. Is this true?

Yes, it is true. However, keep in mind that the SGA constists of 5 main areas and their sum is the size of the SGA.

[Sureshy]

I read somwhere that 10% of memmory should be left available.

The only downside of using up your memmory is paging and swapping. As long as this does not occur, I would have thought that you would be able to increase sga size over 50%.

My SGA is currently 60%. I have no other applications on the server and the system is running fine. No Swapping.

I also consider the amount of memmory PGA for sessions will consume whenever increasing SGA.

Suresh