Re: [PATCHES] Better default_statistics_target

"Kevin Grittner" <Kevin(dot)Grittner(at)wicourts(dot)gov> writes:
> On Thu, Jan 31, 2008 at 10:19 PM, in message
> <200801312319(dot)59723(dot)xzilla(at)users(dot)sourceforge(dot)net>, Robert Treat
> <xzilla(at)users(dot)sourceforge(dot)net> wrote:
>> Bad plans from boosting to 100 or less? Or something much higher?

> I boosted on a large number of columns based on domains. County
> number columns (present in most tables) were set to 80. Some
> columns were set all the way to 1000. When performance tanked, we
> didn't have time to experiment, so we just backed it all out.
> Perhaps I could do some more controlled testing soon against 8.3,
> to narrow it down and confirm the current status of the issue. I
> do seem to recall that simple queries weren't suffering, it was
> those which joined many tables which had multiple indexes.

That fits with the idea that eqjoinsel() is a main culprit.

regards, tom lane