From: | Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> |
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To: | Alex Burkoff <alex(dot)burkoff(at)jivesoftware(dot)com> |
Cc: | "pgsql-general(at)postgresql(dot)org" <pgsql-general(at)postgresql(dot)org> |
Subject: | Re: execution plan is wrong, or the query ? |
Date: | 2012-12-11 17:10:42 |
Message-ID: | 17815.1355245842@sss.pgh.pa.us |
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Lists: | pgsql-general |
Alex Burkoff <alex(dot)burkoff(at)jivesoftware(dot)com> writes:
> I think I am just looking for an opinion on fundamentals. Can WHERE clause impact an OUTER JOIN ?
Sure. I noticed for instance that your query had some outer joins that
were simplified to plain joins as a result of strict WHERE clauses above
them. That's not incorrect.
> What I am seeing is that on 9.2 rows from the joined table are restricted prior to joining them with the rest
> of the tables, and that leads to incorrect results. I have noticed such behaviour only when CASE is used
> in the WHERE clause - straight text comparison does produce correct results.
Oh? Hm, I wonder whether you are needing this fix:
http://git.postgresql.org/gitweb/?p=postgresql.git;a=commitdiff;h=72a4231f0c80f213a4fa75356dc3c6b7c7419059
Although that bug exists in some form back to 7.4, 9.2 had a more
obvious form of the disease, which is what led to its diagnosis.
If you're not running 9.2.2, give that a try and see if it's better.
regards, tom lane
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