Re: HOT patch - version 15

Heikki Linnakangas escribió:
> Alvaro Herrera wrote:
> > Heikki Linnakangas escribió:
> >
> >> Hmm. I wonder if we could prune/defragment in bgwriter?
> >
> > That would be best, if at all possible.  You can prune without accessing
> > anything outside the page itself, right?
>
> Yes, though you do need to have an oldest xmin to determine which tuples
> are dead,

Hmm, well, I think that with the VXID patch it might actually be
possible to get a Xmin without being in a transaction.

> and the removed tuples need to be WAL-logged.

Is this a problem for bgwriter?

--
Alvaro Herrera                                http://www.CommandPrompt.com/
PostgreSQL Replication, Consulting, Custom Development, 24x7 support