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Dear Gurus,
Just now i run the following query:
SQL> select round ((1-(sum(decode(name,'physical reads',value,0)) /
2 (sum(decode(name, 'db block gets',value,0)) +
3 sum(decode(name, 'consistent gets',value,0))))) * 100, 4)
4 hitratio
5 from v$sysstat;
HITRATIO
----------
76.6596
Right now My database hitratio is 76.65. But oracle recommonded hit ratio above 90%.
My Database Buffres(db_cache_size) is 67108864 (Oracle9i Solaris Platform)
How to tune Database Buffers?
Please advise me, Thanks in advance,
Thanks,
Iyyappan.M
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Oracle Certified Master
Oracle Certified Professional 6i,8i,9i,10g,11g,12c
email: ocp_9i@yahoo.com
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go to http://www.hotsos.com and read
Why 99% Database Buffer Cache Hit Ratio is NOT Ok by Cary Millsap
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Originally posted by pando
go to http://www.hotsos.com and read
Why 99% Database Buffer Cache Hit Ratio is NOT Ok by Cary Millsap
Was this about the company in Copenhagen, bla-bla-bla :-)) Come on David, you don't really trust that bull****, do you :-)
[Edited by julian on 08-24-2002 at 10:57 AM]
Oracle Certified Master
Oracle Certified Professional 6i,8i,9i,10g,11g,12c
email: ocp_9i@yahoo.com
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Tuning DB_BLOCK_BUFFERS IN 9i
Hi,
My DB_BLOCK_BUFFERS value is
select state,count(*)
from x$bh
group by state;
state Count(*)
------ --------
0 274
1 7642
3 40
Total DB_BLOCK_BUFFERS = 7956(274+7642+40)
My question is how much value i have to put or increase?
Can u please explain,
Awaiting ur reply,
Thanks in advance,
Iyyappan.M
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Re: Tuning DB_BLOCK_BUFFERS IN 9i
For a start, increase the value by 10%.
Oracle Certified Master
Oracle Certified Professional 6i,8i,9i,10g,11g,12c
email: ocp_9i@yahoo.com
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Start Oracle Enterprise Manager and use the buffer cache advisory to check the effect of adding/removing memory to/from the buffer cache. If adding memory has no significant effect on the ratio why waste it!
Remember, hit ratios are a very basic way of tuning a system. You should consider looking at the YAPP method. Basically this involves eliminating/reducing wait states rather than focusing on hit ratios:
http://www.oracle-base.com/Articles/8i/Statspack8i.asp
http://www.oracle-base.com/Links/yapp_anjo_kolk.pdf
http://www.oracle-base.com/Links/oraperf_bw.pdf
Cheers
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