Re: Really dumb planner decision

Matthew Wakeling <matthew@flymine.org> writes:
> On Thu, 16 Apr 2009, Robert Haas wrote:
>> I hasten to point out that I only suggested raising them to the moon
>> as a DEBUGGING strategy, not a production configuration.

> The problem is that we have created a view that by itself a very
> time-consuming query to answer, relying on it being incorporated into a
> query that will constrain it and cause it to be evaluated a lot quicker.
> This kind of scenario kind of guarantees a bad plan as soon as the number
> of tables reaches from_collapse_limit.

Well, if the payoff for you exceeds the extra planning time, then you
raise the setting.  That's why it's a configurable knob.  I was just
pointing out that there are downsides to raising it further than
absolutely necessary.

            regards, tom lane