>>> On Thu, Jan 31, 2008 at 10:19 PM, in message
<[EMAIL PROTECTED]>, Robert Treat
<[EMAIL PROTECTED]> wrote:
> On Thursday 31 January 2008 09:55, Kevin Grittner wrote:
>>
>> I can confirm that I have had performance tank because of boosting
>> the statistics target for selected columns. It appeared to be time
>> spent in the planning phase, not a bad plan choice. Reducing the
>> numbers restored decent performance.
>
> 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.
-Kevin
---------------------------(end of broadcast)---------------------------
TIP 1: if posting/reading through Usenet, please send an appropriate
subscribe-nomail command to [EMAIL PROTECTED] so that your
message can get through to the mailing list cleanly
