Re: Physical block reads difference

From: David Fitzjarrell <oratune_at_msn.com>
Date: 26 Sep 2002 10:55:34 -0700
Message-ID: <32d39fb1.0209260955.2d7185a2@posting.google.com>

Had you looked further into the view you would have also seen PHYRDS, reporting physical reads, along with PHYBLKRDS, and you would have noticed the difference between the values there. As such, PHYBLKRDS is NOT the same as PHYRDS.

Since a single physical read may span more than one physical block, just as a physical write may write multiple blocks in a single request, it's not surprising that PHYBLKRDS exceeds the value for PHYRDS. David Fitzjarrell

ashok_jayaraman_at_yahoo.com (Jayaraman Ashok) wrote in message news:<7ca2852.0209260221.37be8227_at_posting.google.com>...
> Hi
> I queried the v$sysstat for getting the 'physical reads' on the
> database. I believe this is the number of physical block reads. Now
> querying the sum(phyblkrds) in v$filestat, shouldn't the value be the
> same? I think both the statsistics are one and the same. But then why
> the difference? Kindly explain.
>
> Cheers,
> Ashok
Received on Thu Sep 26 2002 - 12:55:34 CDT