Marty,
When you change from/join collaps_limit pay attention to Genetic Query
Optimizer settings, I believe by default it's "on" (geqo = on).
Specifically look at geqo_threshold parameter (default is 12).
AFAIK, if you don't have intensions to use Genetic Query Optimizer,
geqo_threshold parame
Marty,
* Marty Frasier (m.fras...@escmatrix.com) wrote:
> We have a particular query that takes about 75 minutes to complete. The
> selected execution plan estimates 1 row from several of the outermost
> results so picks nested loop join resolutions. That turns out to be a bad
> choice since act
Tom,
I cranked (join|from)_collapse_limit up to 50, then 500 just to exclude the
limits completey, and attempted the query both times. The planner came up
with an estimate close to the other estimates (1,944,276) and I stopped
actual execution after some length of time.
The t12 subquery is group
Marty Frasier writes:
> We've been using postgreSQL for a few years. This is my first post here
> and first real dive into query plans.
One quick thought is that it's probably worth cranking up
join_collapse_limit and/or from_collapse_limit, since the number of
relations in the query is consider
