Re: Slow inner join, but left join is fast - Mailing list pgsql-performance

From Tom Lane
Subject Re: Slow inner join, but left join is fast
Date
Msg-id 14865.1168454295@sss.pgh.pa.us
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In response to Re: Slow inner join, but left join is fast  ("Jeremy Haile" <jhaile@fastmail.fm>)
Responses Re: Slow inner join, but left join is fast  ("Jeremy Haile" <jhaile@fastmail.fm>)
List pgsql-performance
"Jeremy Haile" <jhaile@fastmail.fm> writes:
> I still don't understand why the inner join would be so different from
> the left join prior to the analyze.

Are you sure you hadn't analyzed in between?  Or maybe autovac did it
for you?  The reason for the plan change is the change from estimating
1 row matching the transaction_date range constraint, to estimating lots
of them, and the join type away up at the top would surely not have
affected that.

            regards, tom lane

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