Re: Autovacuum and OldestXmin

On Thu, 2007-11-22 at 19:02 +0000, Heikki Linnakangas wrote:

> Even if we could use PageIsPrunable, it would be a bad thing from a 
> robustness point of view. If we ever failed to set the Prunable-flag on 
> a page for some reason, VACUUM would never remove the dead tuples.

That's a killer reason, I suppose. I was really trying to uncover what
the thinking was, so we can document it. Having VACUUM ignore it
completely seems wrong.

> Besides, I don't remember anyone complaining about VACUUM's CPU usage, 
> so it doesn't really matter.

Recall anybody saying how much they love it? ;-)

--  Simon Riggs 2ndQuadrant  http://www.2ndQuadrant.com