Re: VACUUM and transactions in different databases

In response to Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>:

> Bill Moran <wmoran(at)collaborativefusion(dot)com> writes:
> > In response to Alvaro Herrera <alvherre(at)commandprompt(dot)com>:
> >> Of course they are able to complete, but the point is that they would
> >> not remove the tuples that would be visible to that idle open
> >> transaction.
>
> > I would expect that, but the OP claimed that vacuum full waited until
> > the other transaction was finished.
>
> No, she didn't claim that. As far as I see she was just complaining
> about the failure to remove dead tuples:
>
> > > > > If I have a running transaction in database1 and try to vacuum
> > > > > database2 but the dead tuples in database2 cannot be removed.

Yes, but a later mail in the thread read:

> > Can you run a "vacuum
> > full", and does it reclaim the space?
>
> I tried but it hangs.
>
> [root(at)conni ~]# ps axw|grep postgres
> 1746 ? S 0:00 postgres: writer process
> 1747 ? S 0:00 postgres: stats buffer process
> 1748 ? S 0:00 postgres: stats collector process
> 2106 pts/1 S 0:00 su postgres
> 2120 pts/1 S+ 0:00 psql postgres
> 2188 ? S 0:04 postgres: postgres dummy1 [local] VACUUM waiting
> 2200 pts/3 S 0:00 su postgres
> 2215 ? S 0:00 postgres: postgres dummy2 [local] idle in transaction
> 2717 pts/2 R+ 0:00 grep postgres

Admittedly, I had the (incorrect) idea that she might need a vacuum
full to reclaim space that lazy vacuum couldn't. And, admittedly, this
wasn't the point of the original post.

--
Bill Moran
Collaborative Fusion Inc.