Hi Guys,
I believe that Ross is on the right track here. I've fought this battle
several times. We have a 1400 connected (300 active) user system that only
needs 50M of shared pool. Most shared pool latch contention comes down to
long lists of chunks on the first and second free list buckets, and most
library cache latch contention comes down to long collision chains hanging
off the hash table. I'd go so far as to say, keep everything of value and
flush the pool routinely.
Regards,
Steve Adams
In article <7fh5ee$et3_at_dfw-ixnews12.ix.netcom.com>,
"Ross Mohan" <postmaster_at_127.0.0.1> wrote:
> >cursor_space_for_time will nearly always end up with a large shared
> >pool.
>
> || I guess i was making the point that the pool was fixed, and too large.
> and that CSFT wasn't helping things by forcing additional pool mgmt
>
> As to what defines a large shared pool depends heavily on the
> >number of applications that the instance has to support. After sizing
> >exercises, I've ended up with Shared Pools ranging from about 20Mb's
> >upto about 400Mb's. Both were about the correct size for the job they
> >were being asked to perform.
>
> || Number of apps and users, plus considerations of pinning, reuse,
> bindvars
> versus not. I haven't ever seen the need ( up to, say, about 500
> concurrent, busy
> thin-client users, multiple apps ) to have a pool larger than 150MB. On
> your
> machine with the 400MB pool, how many users did you have, and was it
> something like an AR/AP or GL setup?
>
> >
> >I think the important thing is that you don't see to much stealing of
> >space from one object class (library cache, dictionary cache, sql area)
> >to fund another. Keep an eye on the v$sgastat output over the course of
> >time.
>
> || This is interesting. Have you experimented at all with monitoring space
> swapping between namespaces in the lib cache, and did you see anything
> there? Thinking about this will be useful, i believe....thanks for
> the thoughts Andrew
>
>
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Received on Tue Apr 20 1999 - 08:28:35 CDT
