Ühel kenal päeval (teisipäev, 8. veebruar 2005, 13:39-0300), kirjutas
Alvaro Herrera:
> On Tue, Feb 08, 2005 at 01:55:47PM +0200, Hannu Krosing wrote:
>
> > So I guess that making it commit and open new transaction at a regular
> > interval (like each minute) during vacuuming single table would not
> > alter its visible behaviour. That would solve my problem of long-running
> > vacuums on large tables polluting unrelated small but heavily updated
> > tables with dead tuples.
>
> Interesting. The problem is that a long running VACUUM on a single
> table will keep in PGPROC a TransactionId that will last very long,
> which will "pollute" every concurrent Snapshot; so smaller tables can't
> be cleaned up because the tuples are visible for the transaction running
> the vacuum -- except that that transaction cannot possibly want to look
> at them.
Exactly. That's what I was trying to describe in my original post.
--
Hannu Krosing <hannu@tm.ee>