From: Tom Lane <tgl@sss.pgh.pa.us>
To: Andreas Kretschmer <akretschmer@spamfence.net>
Cc: pgsql-performance@postgresql.org
Subject: Re: bad execution plan for subselects containing windowing-function
Date: Thu, 14 Jan 2010 12:15:36 -0500
Message-ID: <25448.1263489336@sss.pgh.pa.us> (raw)
In-Reply-To: <20100114170318.GA7634@tux>
References: <20100114170318.GA7634@tux>
Andreas Kretschmer <akretschmer@spamfence.net> writes:
> No question, this is a silly query, but the problem is the 2nd query: it
> is obviously not possible for the planner to put the where-condition
> into the subquery.
Well, yeah: it might change the results of the window functions.
I see no bug here. Your second query asks for a much more complicated
computation, it's not surprising it takes longer.
regards, tom lane
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To: pgsql-performance@postgresql.org
Cc: tgl@sss.pgh.pa.us, akretschmer@spamfence.net
Subject: Re: bad execution plan for subselects containing windowing-function
In-Reply-To: <25448.1263489336@sss.pgh.pa.us>
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