David Gould <da...@sonic.net> writes:
> I also thought about the theory and am confident that there really is no way
> to trick it. Basically if there are enough pages that are different to affect
> the overall density, say 10% empty or so, there is no way a random sample
> larger than a few hundred probes can miss them no matter how big the table is.
> If there are few enough pages to "hide" from the sample, then they are so few
> they don't matter anyway.

> After all this my vote is for back patching too. I don't see any case where
> the patched analyze is or could be worse than what we are doing. I'm happy to
> provide my test cases if anyone is interested.

Yeah, you have a point.  I'm still worried about unexpected side-effects,
but it seems like overall this is very unlikely to hurt anyone.  I'll
back-patch (minus the removal of the unneeded vac_estimate_reltuples

                        regards, tom lane

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