From: Tom Lane <tgl@sss.pgh.pa.us>
To: Jeremy Altavilla <jeremyaltavilla@gmail.com>
Cc: pgsql-performance@postgresql.org
Subject: Re: Analyze results in more expensive query plan
Date: Fri, 17 May 2019 09:35:35 -0400
Message-ID: <6605.1558100135@sss.pgh.pa.us> (raw)
In-Reply-To: <CAG3Nut_TY+cn_THAW3PKE+cNUod8HbaLu+tADrT4vEGcvUWCRg@mail.gmail.com>
References: <CAG3Nut_TY+cn_THAW3PKE+cNUod8HbaLu+tADrT4vEGcvUWCRg@mail.gmail.com>
Jeremy Altavilla <jeremyaltavilla@gmail.com> writes:
> We have several select statements whose performance is greatly improved by
> deleting some stats from pg_statistic.
You might have better results by setting up some "extended stats" for
the combination of bag_type columns that this query depends on. Per your
description, there's a fair amount of cross-column correlation, which
the planner will not expect without some extended stats to tell it so.
https://www.postgresql.org/docs/10/planner-stats.html#PLANNER-STATS-EXTENDED
regards, tom lane
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Subject: Re: Analyze results in more expensive query plan
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