Re: why different db cache hit ratios?

Ibrahim DOGAN wrote:

> the calculation of db cache hit ratios using following methods produce
> different results?
>
> 1- using v$sysstat:
> SELECT 100*(1- ((p.value - l.value - d.value) / s.value)) "Buffer
> Cache Hit Ratio"
> FROM v$sysstat s, v$sysstat l, v$sysstat d, v$sysstat p
> WHERE s.name = 'session logical reads'
> AND d.name = 'physical reads direct'
> AND l.name = 'physical reads direct (lob)'
> AND p.name = 'physical reads';
>
>
> 2- using v$buffer_pool_statistics
>
> select (1-(physical_reads/(db_block_gets+consistent_gets)))*100
> cache_hit_ratio
> from v$buffer_pool_statistics;
>
>
> * So which v$ table has more accurate stats or more reliable ?
>
> Thanks,
> i.d.

Who cares about BDCHR - what platform and version are you anyway?

-- 
Merry Christmas and a Happy New Year,
Frank van Bortel