Re: Need advice on ORA-04030 and pga_aggregate_target parameter

> Daniel and Ronny.. How could percentage of total RAM be a useful
> figure ?
>
> On one hand, assume two GB of ram, and 500 MB of overhead
> for OS etc... Then maximum memory available to Oracle is 1.5 GB,
> or 75% of total RAM. Now add 2GB. Then memory available is
> 3.5 GB, or 87% of total RAM. Therefore, memory available to
> Oracle is not a fixed percentage of total RAM.
>
> On the other hand, the memory required for a given performance
> level depends on a lot of factors, such as block working set, number
> of sessions, etc. These factors are mostly uncorrelated to total
> memory...
>
> Therefore, neither available memory nor required
> memory is a fixed percentage of total memory..
>
> --- Raoul

Raoul,

these percentage values are just imprecise suggestions from Oracle when you initially setup a database. But they are good to know when you don't have much expierience with Oracle. And very different values to your configuration can help reveal misconfigurations.

Fine tuning is only possible when your production database is running some time and you can evaluate the v$*advise dict views, etc.

Regards,
NitelyJoy Received on Tue May 15 2007 - 14:40:48 CDT