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

Andres Freund <andres(at)anarazel(dot)de> writes:
> The default settings currently make it relatively hard to trigger geqo at all.

Yes, and that was intentional. One of the implications of what we're
discussing here is that geqo would get used a lot more for "typical
complex queries" (if there is any such thing as a typical one). So
it's fully to be expected that the fallout would be pressure to improve
geqo in various ways.

Given that we are at the start of the development cycle, that prospect
doesn't scare me --- there's plenty of time to fix whatever needs
fixing. However, I am leaning to the feeling that I don't want to be
putting people in a position where they have no alternative but to use
geqo. So adjusting rather than removing the collapse limits is seeming
like a good idea.

regards, tom lane