Re: pgstat_drop_relation bugfix

I wrote:
> What I'm inclined to propose is that we just remove the
> pgstat_drop_relation() call from smgr_internal_unlink, and rely entirely
> on VACUUM to clean out dead entries in the pgstats data.

On checking the CVS history, that in fact is how the code worked before
8.1.3, when I introduced the bogus call in a fit of over-optimization :-(.
I vaguely recall thinking that the chance of losing data would be small
and pgstat is subject to losing data anyway. However, we are definitely
moving (slowly) in the direction of making pgstat more trustworthy, so
it's probably best not to take the risk of dropping useful stats.

Call removed from 8.1.x and up.

regards, tom lane