Re: RFC: Timing Events

On Fri, Nov 2, 2012 at 8:54 AM, Josh Berkus <josh(at)agliodbs(dot)com> wrote:

> Greg,
>
> First off, let me again praise the great work you and Peter are doing in
> this area.
> > Modeling this on pg_stat_statements includes the hope of packaging it as
> > an extension with minor core hooks, and the idea that there would be a
> > fixed size list of timing events available at any time. Consider it a
> > FIFO queue built using a circular buffer. Dump events into there and
> > provide a way to view them. If some fall out before they're
> > analyzed/saved, that doesn't seem a problem for now.
>
> Agreed.
>
> > If you want 100%
> > durable, the log is still available. Eventually I'd like a consumer for
> > these that wrote them to a history table as an option, but that seems a
> > second priority after getting them into memory in the first place.
>
> Yes, and easy for users/tools to implement once the basic data is out
> there.
>
> > I'd
> > like that consumer thing for pg_stat_statements too, but so far we're
> > getting by without it. It seems like something that might benefit from
> > the in-core queuing work one day too.
>
> Well, we could actually use such a thing in general, and not just for
> the timing events. For example, it would be really useful to be able to
> see, for example, pg_stat_user_tables from 2 days ago to estimate table
> growth and activity, or pg_stat_replication from 10 minutes ago to
> average replication lag. There was a plug-in tool for this, I think
> Itagaki developed it. Anyone remember what/where it is?
>
pg_statsinfo perhaps? It is used for stat info management:
http://pgfoundry.org/projects/pgstatsinfo/
--
Michael Paquier
http://michael.otacoo.com