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Home -> Community -> Mailing Lists -> Oracle-L -> RE: negative value for buffer cache hit ratio
Andrey,
I am not into cache hit ratios, but got curious about your negative value.
So I casually searched Metalink for 'negative value for hit ratio'. And got a hit on 'MROC: I am receiving a negative Buffer Cache hit ratio' thread. You may want to check it out, there seems to be a new formula for hit ratio computation in 8i/9i.
HTH, Regards,
> -----Original Message-----
> From: Andrey Bronfin [SMTP:andreyb_at_elrontelesoft.com]
> Sent: Tuesday, August 07, 2001 12:51 PM
> To: Multiple recipients of list ORACLE-L
> Subject: negative value for buffer cache hit ratio
>
>
> Dear gurus !
> I have a negative value for buffer cache hit ratio in my DB which is up
> for
> some 4 months .
> Any ideas why ?
> Thanks in advance.
>
> SQL> SELECT (1 - (SUM(DECODE(a.name,'physical reads',value,0)) /
> 2 (SUM(DECODE(a.name,'consistent gets',value,0)) +
> 3 SUM(DECODE(a.name,'db block gets',value,0))))) * 100 "buffer cache
> hit
> ratio"
> 4 FROM v$sysstat a;
>
> buffer cache hit ratio
> ----------------------
> -52.99284
>
> --
> Please see the official ORACLE-L FAQ: http://www.orafaq.com
> --
> Author: Andrey Bronfin
> INET: andreyb_at_elrontelesoft.com
>
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-- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: Deshpande, Kirti INET: kirti.deshpande_at_verizon.com Fat City Network Services -- (858) 538-5051 FAX: (858) 538-5051 San Diego, California -- Public Internet access / Mailing Lists -------------------------------------------------------------------- To REMOVE yourself from this mailing list, send an E-Mail message to: ListGuru_at_fatcity.com (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing).Received on Tue Aug 07 2001 - 12:05:41 CDT
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