Re: WIP: cross column correlation ...

> I think there would be value in giving the DBA an easier way to see
> which tables are hot, but I am really leery about the idea of trying
> to feed that directly into the query planner. I think this is one of
> those cases where we let people tune it manually for starters, and
> then wait for feedback. Eventually someone will say "oh, I never tune
> that by hand any more, ever since I wrote this script which does the
> following computation... and I just run it out cron". And then we
> will get out the party hats. But we will never get the experience we
> need to say what that auto-tuning algorithm will be unless we first
> provide the knob for someone to fiddle with manually.

I'm not disagreeing with that. I'm saying "first, we give DBAs a way to
see which tables are currently hot". Such a feature has multiple
benefits, making it worth the overhead and/or coding effort.

Whether we're shooting for autotuning or manual tuning, it starts with
having the data.

--
-- Josh Berkus
PostgreSQL Experts Inc.
http://www.pgexperts.com