Re: v$sql.disk_reads versus v$sql.physical_read_requests

From: Tanel Poder <tanel_at_tanelpoder.com>
Date: Fri, 7 Jun 2013 20:08:58 +0300
Message-ID: <CAMHX9JJBoEOQMkLfqAEhBCaNhPYJJeyR2GBMQPT0qenLmkTCRA_at_mail.gmail.com>

disk_reads is number of blocks read
physical_read_requests is the number of IO requests done so if all you do is single block reads, the disk_reads = physical_read_requests

but if you also do multiblock reads, then the dist_reads should be bigger

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On Fri, Jun 7, 2013 at 8:03 PM, Walker, Jed S
<Jed_Walker_at_cable.comcast.com>wrote:



> I was looking over v$sql and noticed it has disk_reads and

> physical_read_requests. I couldn't tell from the docs exactly what the

> difference is.

> I'm guessing disk_reads is the number of disk reads requested, and

> physical_read_requests is how many reads were actually required from the

> disk (maybe because of diffs in db block size and disk block size?)

> Curious if anyone knows for certain?

>

> thanks

>

> --

> http://www.freelists.org/webpage/oracle-l

>

>

>



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Received on Fri Jun 07 2013 - 19:08:58 CEST