RE: Do you use KEEP Buffer Pool in your production system?
- From: "Larry G. Elkins" <elkinsl@xxxxxxxxx>
- To: <kamusis@xxxxxxxxx>, "'oracle_l'" <Oracle-L@xxxxxxxxxxxxx>
- Date: Fri, 26 Mar 2010 09:41:43 -0500
We've used once for a vendor application and DB, but it was *far* down the
priority list after addressing other items that provided
much bigger bang for the buck. The targeted on-line business critical processes
did indeed improve, marginally, but enough to be
noticed and appreciated, while some of the less important, response time
perspective, processes saw a slight degradation. The impact
was measured and quantified. Used a combination of all three pools, with those
huge segments "polluting" the pool assigned to
RECYCLE and letting them duke it out there, more critical segments in KEEP, and
everything else in the DEFAULT. Once again, only
done after bigger bang for the buck things were addressed, including why are
you *hitting* those segments so frequently.
With a new version of the vendor software and an upgrade to the DB about to
roll out, we are going back to strictly DEFAULT and will
re-consider if things point to it possibly helping. And as Mark alluded to,
over time it has become un-tuned somewhat and not quite
providing the initial gains that were seen.
Larry G. Elkins
Refer to AskTom:
http://asktom.oracle.com/pls/asktom/f?p=100:11:0::::P11_QUESTION_ID:1590999000346302363
Tom Kyte said:
I would not use the keep pool, the default buffer cache is almost certainly
better than good enough.
The keep buffer would definitely be in the SGA, it is just another buffer
cache.
What do you think? Do you use KEEP Buffer Pool in your production system?
Other related posts:
