Bob Jones wrote:
> "DA Morgan" <damorgan_at_psoug.org> wrote in message
> news:1145489802.204935_at_yasure.drizzle.com...
>> Bob Jones wrote:
>>> "Poh Tien Lye" <pohtl_at_singnet.com.sg> wrote in message
>>> news:e25jd2$anb$1_at_reader01.singnet.com.sg...
>>>> Hi,
>>>>
>>>> Recently, I found that my Oracle database (8.1.7.4) on Windows NT
>>>> service
>>>> pack 6
>>>> response time has increased significantly. I did a check and found the
>>>> buffer chache hit ratio
>>>> was down to less than 0.20. However, the ratio does not improve even
>>>> when I
>>>> increase the
>>>> db_buffer from 17MB to 38MB. The ratio still drop to 0.20 after 8 hrs
>>>> of
>>>> operation.
>>> Are you sure the hit ratio is calculated correctly? That is very low. How
>>> much data are you dealing with? 38MB is still too small for an average
>>> database.
>> High? Low? What's the difference. Hit ratios have been proven irrelevant.
>
> Irrelevant to performance? I have not yet seen that prove.
1. Read books by Tom Kyte
2. Read books by Jonathan Lewis
3. Read the archives of this usenet group specifically looking for posts
by Richard Foote and Howard Rogers (as well as Jonathan Lewis).
4. Hit ratios have been dead, buried, and fossilized for some years now.
--
Daniel A. Morgan
http://www.psoug.org
damorgan_at_x.washington.edu
(replace x with u to respond)
Received on Thu Apr 20 2006 - 13:27:04 CDT
