Re: new BUG: "postgresql 9.2.3: very long query time"

Jeff Janes <jeff.janes@gmail.com> writes:
> The slowness was introduced with this:
>     Use parameterized paths to generate inner indexscans more flexibly.

Try increasing from_collapse_limit to 11 or more.

I'm not exactly sure why the param-path patch might have changed this
behavior, but in any case the collapse limits ought to be the first
thing you think of when you see a crappy plan for a many-relation query.

The curious join nesting in this query makes me wonder if perhaps it was
hand-optimized to fit the behavior of some old version of the planner ...

            regards, tom lane