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Re: How to figure out how many IOs a SQL costs ?

From: Bass Chorng <bchorng_at_yahoo.com>
Date: 16 Oct 2002 17:52:14 -0700
Message-ID: <bd9a9a76.0210161652.385a2845@posting.google.com>


"Anton Buijs" <aammbuijs_at_xs4all.nl> wrote in message news:<aoi4v5$lks$1_at_news1.xs4all.nl>...
> View V$SESS_IO shows some IO info per session (not writes).
> Another way is to activate tracing for the session and run tkprof on the
> trace file.
> The output of tkprof shows logical and physical IO per statement.
>

  I might be wrong here, but isn't v$sess_io and tkprof all showing   # of blocks, not # of IOs ? I am interested to know # of IOs, not   blocks, because blocks could be a combination of sequential read   and scattered read and the # of block/ per IO could be differnt.

  For example, in tkprof, the column Disk indicates number of BLOCKs   read from disk, not number of disk access, if I am correct. The same   with v$sess_io, all values in there are # of blocks. Also the same   with disk_reads in v$sql.. Received on Wed Oct 16 2002 - 19:52:14 CDT

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