Re: Force another plan. - Mailing list pgsql-performance

Fredrik Olsson <fredrik.olsson@treyst.se> writes:
>         ->  Seq Scan on t_entities  (cost=0.00..1.49 rows=7 width=4)
> (actual time=404.539..409.302 rows=2 loops=1)
>               Filter: ((haveaccess(createdby, responsible, "class",
> false) OR CASE WHEN (partof = 'contacts'::name) THEN
> ischildof(ancestorof(me()), "ID") ELSE false END) AND (subplan))
>               SubPlan
>                 ->  Function Scan on alleventoccurances
> (cost=0.00..12.50 rows=1000 width=8) (actual time=27.871..27.871 rows=0
> loops=14)

This seems to be your problem right here: evaluating that subplan for
each row of t_entities is pretty expensive, and yet the planner's
estimating a total cost of only 1.49 to run the scan.  What PG version
is this?  AFAICT we've accounted for subplan costs in scan quals for
a long time, certainly since 7.4.  Can you put together a self-contained
test case for this?

            regards, tom lane