Re: HOT patch - version 15

Bruce Momjian wrote:
> Tom Lane wrote:
>> The we-already-pinned-the-page problem is a bit nasty but may not be
>> insurmountable.

If you find a way, that would be great.

> 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.

--
  Heikki Linnakangas
  EnterpriseDB   http://www.enterprisedb.com