Re: Buffer cache hits %
From: Jiliang Chiu <lchiu_at_bellsouth.net>
Date: Thu, 15 Jul 1999 15:20:34 -0500
Message-ID: <Urqj3.7410$xK4.30626_at_news3.atl>
Date: Thu, 15 Jul 1999 15:20:34 -0500
Message-ID: <Urqj3.7410$xK4.30626_at_news3.atl>
Kevin:
The hit ratio should be 95 - 100%.
You can use X$KCBRRH (raise buffer hits)
and X$KCBCBH (crushes buffe hits) to check the statistics for
adding or removing buffers.
(connect as sys)
Run UTLBSTAT and UTLESTAT to get detials of your
performance information.
(connect as intenal will do)
Start databaase for sometime before you run UTLBSTAT,
try to collect whole session.
JC
Received on Thu Jul 15 1999 - 22:20:34 CESTKevin Gillins <kevin_gillins_at_compuserve.com> wrote in message news:O41ialrz#GA.309_at_nih2naae.prod2.compuserve.com...I have a question about the buffer cache hits ratio we are experiencing.We are on 7.3.3.5 database using 10.7 oracle apps most all products. Apx 100+ users.The database size is apx 40 gig. We are on HP 4 processors with 2.5 gig memory.There are 2 instances both the same size (prod and test). The shared pool is setat 250,000,000 running 6 db writers. The production instance is on EMC disks.My main question is the buffer cache hit% is sitting at 90% in general. Is this good, bad orreal bad. I want to get a feel. I have tried increasing the shared pool and db_block_buffers.What other settings if any would improve this statistic. What stats could I check to seewhat contributes to the 10% miss?Your suggestions and answers are appreciated.
--
Kevin Gillins
Management Information Consulting
Boston Office
978-887-3300