Re: pgsql: Avoid having vacuum set reltuples to 0 on non-empty relations in

On 2017-03-16 23:37:06 -0400, Tom Lane wrote:
> Andrew Gierth <rhodiumtoad(at)postgresql(dot)org> writes:
> > Avoid having vacuum set reltuples to 0 on non-empty relations in the
> > presence of page pins, which leads to serious estimation errors in the
> > planner.
>
> Hm, buildfarm results suggest this test is not entirely stable:
>
> https://buildfarm.postgresql.org/cgi-bin/show_log.pl?nm=crake&dt=2017-03-17%2000%3A47%3A57
>
> I have not looked very closely, but I'm suspicious that the test case
> depends on no autovacuum transactions running concurrently with it.
> Disabling autovac on the table itself is not enough to control whether
> global xmin is being held back by some other autovac transaction
> somewhere.

Yea, brought it up on IRC too - he's gone for the night (Europe). I
suspect changing things > might do the trick.

- Andres