Re: Load Distributed Checkpoints, take 3

On Mon, 25 Jun 2007, Tom Lane wrote:

> right now, BgBufferSync starts over from the current clock-sweep point
> on each call --- that is, each bgwriter cycle.  So it can't really be
> made to write very many buffers without excessive CPU work.  Maybe we
> should redefine it to have some static state carried across bgwriter
> cycles

The LRU portion restarts like that, and it's certainly not optimal.  But
the auto-tuning LRU patch that's already near application makes this much
less of an issue because it only does real work when buffers have been
allocated, so the sweep point will have moved along.  I'll add this idea
to my list of things that would be nice to have as part of a larger
rewriter, I think it's more trouble than it's worth to chase right now.

--
* Greg Smith gsmith@gregsmith.com http://www.gregsmith.com Baltimore, MD