Re: *_collapse_limit, geqo_threshold

On Wed, Jul 8, 2009 at 4:57 PM, Tom Lane<tgl@sss.pgh.pa.us> wrote:
> Well, the reason I'm not voting for #3 is that it looks like a lot of
> work to implement something that would basically be a planner hint,
> which I'm generally against; furthermore, it's a hint that there's been
> no demand for.  (We're not even certain that anyone is using the ability
> to *fully* specify the join order, much less wanting some undetermined
> compromise between manual and automatic control.)  And anyway I didn't
> hear anyone volunteering to do it.  So the realistic alternatives are
> #1, #2, or "do nothing"; and out of those I like #2.

I took a look at this and it seems that #3 can be implemented with
essentially no additional code (the handful of lines I added where
more than balanced out by some simplifications in ruleutils.c).  Of
course you still don't have to like it.  :-)

Patch attached.

...Robert