Re: Review remove {join, from}_collapse_limit, add enable_join_ordering

Andres Freund <andres(at)anarazel(dot)de> writes:
> The queries on the second reporting schema unfortunately are different. Its the
> one were I copied the crazy example I attached in the original thread.
> With geqo=off a good part of the queries used daily use too much memory to plan
> sensibly and geqo=on outright fails with:
> "Error: Failed to make a valid plan"
> on some.

We're not going to be able to fix this unless you show us examples.

> Noticeable even some plans which were plannable in reasonable time before now
> are problematic with enable_join_ordering=false!

And this even more so --- it doesn't make any sense at all.

> So, while I think the changes are principally a good idea, as
> {from,join}_collapse_limit are a bit confusing options, I personally! do not
> think geqo is ready for it today, especially as the benefit is relatively
> small.

In general I think that any such bugs are there anyway and need to be
fixed anyway.

regards, tom lane