Re: eliminating records not in (select id ... so SLOW?

Ivan Sergio Borgonovo <mail@webthatworks.it> writes:
> Well I reached 3Gb of work_mem and still I got:

> "Seq Scan on catalog_categoryitem  (cost=31747.84..4019284477.13
> rows=475532 width=6)"
> "  Filter: (NOT (subplan))"
> "  SubPlan"
> "    ->  Materialize  (cost=31747.84..38509.51 rows=676167 width=8)"
> "          ->  Seq Scan on catalog_items  (cost=0.00..31071.67
> rows=676167 width=8)"

Huh.  The only way I can see for that to happen is if the datatypes
involved aren't hashable.  What's the datatypes of the two columns
being compared, anyway?

            regards, tom lane