Re: Abysmal hash join

Florian Weimer <fweimer@bfk.de> writes:
>          ->  Bitmap Index Scan on large_rel_1_field_1  (cost=0.00..2003.09 rows=193739 width=0) (actual
time=0.148..0.148rows=12 loops=1) 
>                Index Cond: (n.field_1 = "outer".field_2)

What you need to look into is why that rowcount estimate is off by four
orders of magnitude.

The estimate on the smaller table is only off by a factor of 75 but
that's still pretty darn awful.  Are the statistics up to date?  Maybe
larger stats targets would help.

            regards, tom lane