Re: Exposing the Xact commit order to the user

Excerpts from Robert Haas's message of dom may 23 20:38:14 -0400 2010:
> On Sun, May 23, 2010 at 4:21 PM, Jan Wieck <JanWieck(at)yahoo(dot)com> wrote:
> > The system will have postgresql.conf options for enabling/disabling the
> > whole shebang, how many shared buffers to allocate for managing access
> > to the data and to define the retention period of the data based on data
> > volume and/or age of the commit records.
>
> It would be nice if this could just be managed out of shared_buffers
> rather than needing to configure a separate pool just for this
> feature.

FWIW we've talked about this for years -- see old discussions about how
pg_subtrans becomes a bottleneck in certain cases and you want to
enlarge the number of buffers allocated to it (probably easy to find by
searching posts from Jignesh). I'm guessing the new notify code would
benefit from this as well.

It'd be nice to have as a side effect, but if not, IMHO this proposal
could simply use a fixed buffer pool like all other slru.c callers until
someone gets around to fixing that. Adding more GUC switches for this
strikes me as overkill.

--
Álvaro Herrera <alvherre(at)alvh(dot)no-ip(dot)org>