Re: Autovacuum versus rolled-back transactions

[Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>]

Alvaro Herrera <alvherre(at)commandprompt(dot)com> writes:
> If we apply Heikki's idea of advancing OldestXmin, I think what we
> should do is grab the value from pgstats when vacuum starts, and each
> time we're going to advance OldestXmin, grab the value from pgstats
> again; accumulate the differences from the various pgstat grabs.  At the
> end we send the accumulated differences as the new dead tuple count.

Considering that each of those values will be up to half a second old,
I can hardly think that this will accomplish anything except to
introduce a great deal of noise ...

			regards, tom lane