Subject: Re: query performance issue
To: pgsql-performance@postgresql.org
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From: Gunther <raj@gusw.net>
Message-ID: <31c10833-9d19-dfa5-1cab-43eaae097828@gusw.net>
Date: Wed, 15 Nov 2017 14:58:17 -0500
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On 11/15/2017 8:12, Pavel Stehule wrote:
> There is wrong plan due wrong estimation
>
> for this query you should to penalize nested loop
>
> set enable_nestloop to off;
>
> before evaluation of this query

You are not the only one with this issue. May I suggest to look at this 
thread a little earlier this month.

http://www.postgresql-archive.org/OLAP-reporting-queries-fall-into-nested-loops-over-seq-scans-or-other-horrible-planner-choices-tp5990160.html

where this has been discussed in some length.

regards,
-Gunther


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    <br>
    <div class="moz-cite-prefix">On 11/15/2017 8:12, Pavel Stehule
      wrote:<br>
    </div>
    <blockquote type="cite"
cite="mid:CAFj8pRC6xh=HDq1jwxW8n1Ct8=FbbdqHcx_VFHNCdNUz41rTWQ@mail.gmail.com">
      <div dir="ltr">
        <div class="gmail_extra">
          <div class="gmail_quote">There is wrong plan due wrong
            estimation <br>
            <div><br>
            </div>
            <div>for this query you should to penalize nested loop</div>
            <div><br>
            </div>
            <div>set enable_nestloop to off;</div>
            <div><br>
            </div>
            <div>before evaluation of this query</div>
          </div>
        </div>
      </div>
    </blockquote>
    <br>
    You are not the only one with this issue. May I suggest to look at
    this thread a little earlier this month.<br>
    <br>
<a class="moz-txt-link-freetext" href="http://www.postgresql-archive.org/OLAP-reporting-queries-fall-into-nested-loops-over-seq-scans-or-other-horrible-planner-choices-tp5990160.html">http://www.postgresql-archive.org/OLAP-reporting-queries-fall-into-nested-loops-over-seq-scans-or-other-horrible-planner-choices-tp5990160.html</a><br>
    <br>
    where this has been discussed in some length.<br>
    <br>
    regards,<br>
    -Gunther<br>
    <br>
    <br>
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