Re: nested query vs left join: query planner very confused

On Wed, 27 Nov 2013 13:04:54 -0500, David Rysdam <drysdam(at)ll(dot)mit(dot)edu> wrote:
> We deliberately try to keep our queries fairly simple for several
> reasons. This isn't the most complicated, but they don't get much more
> than this. I'll have them start with 10MB and see what they get.

10MB was enough to get that query to come back instantly. The same query
on some larger tables were still slow so we ended up bumping up to 50MB
to get the entire job done. That probably sounds like a lot to you guys,
but now that we know the behavior and what kind of queries we have I
think we're OK.

(And if you want a shocker, when I looked at our own DB, we've had
work_mem set to 250MB on a lot of our servers and 1GB on our main
production machine. Heh. I've got some PG tuning books here next to me
now...)

Thanks!