Thread: Help understanding stat tables

I just want to make sure that I am interpreting this data correctly.

From pg_statio_user_tables, I have pulled relname, heap_blks_read,
heap_blks_hit.  I get several rows like this:
relname                heap_bkls_read    heap_blks_hit
 clmhdr                           8607161            196547165







                                                                                               


So this means that I am getting over a 100% cache hit ratio for this table,
right?  If not, please help me understand what these numbers mean.

Thanks,

Chris

I think I have figured my problem out.

I was taking heap_blks_hit / heap_blks_read for my hit pct.

It should be heap_blks_hit/(heap_blks_read+heap_blks_hit), correct?

Thanks
On Wednesday 21 April 2004 11:34, Chris Hoover wrote:
> I just want to make sure that I am interpreting this data correctly.
>
> From pg_statio_user_tables, I have pulled relname, heap_blks_read,
> heap_blks_hit.  I get several rows like this:
> relname                heap_bkls_read    heap_blks_hit
>  clmhdr                           8607161            196547165
>
>
> So this means that I am getting over a 100% cache hit ratio for this table,
> right?  If not, please help me understand what these numbers mean.
>
> Thanks,
>
> Chris
>
>
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"Chris Hoover" <revoohc@sermonaudio.com> writes:
> I was taking heap_blks_hit / heap_blks_read for my hit pct.
> It should be heap_blks_hit/(heap_blks_read+heap_blks_hit), correct?

Right.

            regards, tom lane