Re: why does this query not use a parallel query - Mailing list pgsql-performance

From Tom Lane
Subject Re: why does this query not use a parallel query
Date
Msg-id 30033.1520009080@sss.pgh.pa.us
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In response to why does this query not use a parallel query  (Dave Cramer <davecramer@gmail.com>)
List pgsql-performance
Dave Cramer <davecramer@gmail.com> writes:
> Have a query:
> explain analyze SELECT minion_id FROM mob_player_mob_118 WHERE player_id =
> 55351078;

>  Index Only Scan using mob_player_mob_118_pkey on mob_player_mob_118
> (cost=0.44..117887.06 rows=4623076 width=4) (actual time=0.062..3716.105
> rows=4625123 loops=1)

I don't think we have parallel IOS yet (I might be wrong).  If so,
it probably thinks this is cheaper than the best available parallel plan.

> If I just get the count it will use a parallel query

Likely a parallelized aggregation.

            regards, tom lane


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