Re: add_path optimization

>>> Robert Haas <robertmhaas@gmail.com> wrote: 
> FYI, I retested my queries on REL8_3_STABLE and the results were not
> all that different from CVS HEAD.  So the problem is apparently
> specific to something your query is doing that mine isn't., rather
> than a general slowdown in planning (or else one of us goofed up the
> testing).
I know you said size doesn't matter, but just for the record, the ten
tables I loaded for this test put the database at 56G.  I'm pulling
information together to share on this, but I was wondering: is there
any possibility that the tendency to use index scans in nested loops
(given the table sizes and the availability of useful indexes)
contributes to the difference?
Other possible factors:
Most keys are multi-column and include varchar-based data types.
Most columns are defined via domains.
(More info to follow.)
-Kevin