Tom Lane said the following on 05/11/2009 07:02 PM:
where we're off by a factor of 1500+ :-(
I think most likely the ~~ operator is the biggest problem.
Unfortunately 8.1's estimator for ~~ is not terribly bright. You could
try increasing your statistics target but I don't think it will help
much. Is there any chance of updating to 8.2 or later? 8.2 can do
significantly better on this type of estimate as long as it has enough
stats.
In any case I'd suggest raising default_statistics_target to 100 or so,
as you seem to be running queries complex enough to need good stats.
But I'm not sure that that will be enough to fix the problem in 8.1.
regards, tom lane
I should have mentioned the statistics for every column are already set
to 1000. I guess we'll have to add an upgrade to the project list.
Thanks for the info.
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