From: Tom Lane <tgl@sss.pgh.pa.us>
To: Simon Riggs <simon@2ndquadrant.com>
Cc: Andrew Sullivan <ajs@crankycanuck.ca>
Cc: pgsql-performance@postgresql.org
Subject: Re: Some queries starting to hang
Date: Tue, 06 Jun 2006 11:06:09 -0400
Message-ID: <17426.1149606369@sss.pgh.pa.us> (raw)
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Simon Riggs <simon@2ndquadrant.com> writes:
> You mentioned it would be good if the OP had delivered an EXPLAIN
> ANALYZE; I agree(d). The lack of EXPLAIN ANALYZE is frequently because
> you can't get them to run to completion - more so when the query you
> wish to analyze doesn't appear to complete either.
Well, he could have shown EXPLAIN ANALYZE for the server that was
managing to run the query in a reasonable amount of time.
> The idea I just had was: why do we need EXPLAIN ANALYZE to run to
> completion? In severe cases like this thread, we might be able to
> discover the root cause by a *partial* execution of the plan, as long as
> it was properly instrumented. That way, the OP might have been able to
> discover the root cause himself...
I don't think that helps, as it just replaces one uncertainty by
another: how far did the EXPLAIN really get towards completion of the
plan? You still don't have any hard data.
regards, tom lane
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To: pgsql-performance@postgresql.org
Cc: tgl@sss.pgh.pa.us, simon@2ndquadrant.com, ajs@crankycanuck.ca
Subject: Re: Some queries starting to hang
In-Reply-To: <17426.1149606369@sss.pgh.pa.us>
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