Re: Update Perrformance with nested loop vs. merge-join

"Nathan Boley" <nate(dot)boley(at)gmail(dot)com> writes:
> Merge Join (cost=883182.60..1024622.03 rows=6873573 width=89)
> Merge Cond: ("outer".pkeycolumn1 = "inner".pkey)
> -> Sort (cost=93387.50..94711.01 rows=529404 width=18)
> Sort Key: table2.pkey
> -> Seq Scan on table2 (cost=0.00..15037.04 rows=529404 width=18)
> -> Sort (cost=789795.10..795605.39 rows=2324116 width=81)
> Sort Key: table1.pkeycolumn1
> -> Seq Scan on table1 (cost=0.00..71900.16 rows=2324116 width=81)

> This seems like it *should* be the best query to me, but when I try and run
> it it takes forever.

What PG version is this, and what have you got work_mem (or sort_mem)
set to? I'm betting the sorts are slow ...

regards, tom lane