Re: Explain Plan
From: Niall Litchfield <niall.litchfield_at_dial.pipex.com>
Date: Fri, 4 Feb 2005 21:03:47 -0000
Message-ID: <4203e324$0$19158$cc9e4d1f_at_news-text.dial.pipex.com>
Received on Fri Feb 04 2005 - 22:03:47 CET
Date: Fri, 4 Feb 2005 21:03:47 -0000
Message-ID: <4203e324$0$19158$cc9e4d1f_at_news-text.dial.pipex.com>
<amerar_at_iwc.net> wrote in
message news:1107548968.828618.55110_at_l41g2000cwc.googlegroups.com...
>
> Actually you are wrong. We are using Locally Managed. And again,
> there is nothing wrong with the explain plan I displayed.
>
> What I am asking for is how or where I can find info on understand that
> hunk of junk.
> Actually you are wrong. We are using Locally Managed. And again,
> there is nothing wrong with the explain plan I displayed.
>
> What I am asking for is how or where I can find info on understand that
> hunk of junk.
Sybrand was correct about the reference manual -
the performance tuning guide does tell you about access methods, types of join
etc. http://download-west.oracle.com/docs/cd/B10501_01/server.920/a96533/toc.htm is the reference, you'll see it tells you about access
paths and join methods, about explain plan and about tkprof. Its the place to
start.
In *general* you read inside out with the results
[Quoted] of the inner operation providing the input rowset for the outer operation. If
you are running TKPROF with the explain= parameter don't, the plans it gives are
those that would be executed if the statement ran now in the environment as it
is now for the user you use to explain it. The only way to get the plan that
actually was executed is to use the STAT lines (which is what tkprof does if you
don't use explain= ) in the trace file or to query v$sql_plan if you have that
view in the version you are running.