"Joel Fradkin" <jfradkin@wazagua.com> writes:
> Turning off merg joins seems to of done it but what do I need to do so I am
> not telling the system explicitly not to use them, I must be missing some
> setting?
> " -> Hash Left Join (cost=185.57..226218.77 rows=177236 width=75) (actual
> time=21.147..2221.098 rows=177041 loops=1)"
> " Hash Cond: (("outer".jobtitleid = "inner".id) AND
> (("outer".clientnum)::text = ("inner".clientnum)::text))"
It's overestimating the cost of this join for some reason ... and I
think I see why. It's not accounting for the combined effect of the
two hash clauses, only for the "better" one. What are the statistics
for tbljobtitle.id and tbljobtitle.clientnum --- how many distinct
values of each, and are the distributions skewed to a few popular values?
regards, tom lane
