Hi,
On 2017-01-18 21:09:52 -0500, Tom Lane wrote:
> I wrote:
> > If you don't want an ORDER BY, maybe turn off enable_hashagg for
> > these queries? But you'll get the same plan either way.
>
> Or not ... I forgot it has a better model of the rowcount changes now:
> regression=# set enable_hashagg TO 0;
> SET
> regression=# explain SELECT few.dataa, count(*), min(id), max(id),
> unnest('{1,1,3}'::int[]) FROM few WHERE few.id = 1 GROUP BY few.dataa,
> unnest('{1,1,3}'::int[]);
> QUERY PLAN
> -----------------------------------------------------------------------
> GroupAggregate (cost=39.94..45.99 rows=4 width=52)
> Group Key: dataa, (unnest('{1,1,3}'::integer[]))
> -> Sort (cost=39.94..40.94 rows=400 width=40)
> Sort Key: dataa, (unnest('{1,1,3}'::integer[]))
> -> ProjectSet (cost=0.00..22.66 rows=400 width=40)
> -> Seq Scan on few (cost=0.00..20.62 rows=4 width=36)
> Filter: (id = 1)
> (7 rows)
> So which plan would you rather test?
That looks good to me. Will add.
Thanks,
Andres
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