Re: SGA size

"Roel Toledo" <dontsendmailstome_at_bogusmail.com> wrote in message news:SujF7.156116$3d2.5757458_at_bgtnsc06-news.ops.worldnet.att.net...
> > Other than that, there's not a lot to sizing the SGA in purely 'how do I
> do
> > it' terms. Other posters are hinting at the fact that there are "right"
> > sizes for all these parameters, and that determining what those right
> sizes
> > are is a matter of performance tuning.
>
> Not really right *sizes* for all the parameters but right *performance*
> under which the parameters must aim to reach. One performance goal that
> must be reached when tuning the database is a reloads to pins ratio of 1
> percent (as can be checked in v$librarycache). Another perfomance area
that
> must be reached is buffer hit ratio which must be 90% or higher according
to
> Oracle. The latch hit ratio must be 99 percent.
>

Perhaps it's a language thing, but what you have posted is precisely what I said. "determining those right sizes...is...as matter of performance tuning". And performance tuning is all about measuring these ratios (and others), and then adjusting the sizes of various SGA components to make them reach the required ratios.

And whatever those sizes are when you reach the ratios are, ipso facto, the "right size" for that particular environment.

I've heard of quibbling, but this is getting OTT!

HJR Received on Mon Nov 05 2001 - 02:05:26 CST