Re: HOT patch - version 15

On Mon, 2007-09-10 at 09:03 +0100, Heikki Linnakangas wrote:

> > As I understand it, there are two HOT features:
> >
> >     Single-chain pruning, which trims HOT chains but doesn't reuse
> >         the space
> >
> >     Defragementation, which prunes the entire page and reuses space
> >         and handles deleted rows, etc.
>
> I'm repeating myself, but I would split that second operation into two
> parts while we think about this: pruning the entire page, and
> defragmenting (PageRepairFragmentation). Tom wondered why they're
> separated in the patch. As the patch stands, there is no reason, but I
> feel that separating them and doing them at different times might be an
> important piece in the puzzle.

Yes, it does seem important to keep that separation, since it is
possible to do these things at different times, even if, for now, we
choose not to.

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