Re: pre-algebra discussion - HOT?

[oops - sent only to Rich, and fixed attribution this time]

On 9/20/07, Rich Shepard <rshepard(at)appl-ecosys(dot)com> wrote:
> On Thu, 20 Sep 2007, Jeff Davis wrote:
>
> > I've been following HOT for a while, and I don't mind sharing. I do not
> > have in-depth knowledge on it, however.
>
> Jeff/Selena,
>
> For those of us who are NOT HOT, please explain what HOT is/does. In two
> sentences.
In one sentence:
HOT (Heap Overflow Tuple) is intended to improve update behavior on
heavily updated tables.

From Pavan Deolasee:

"HOT stands for Heap Overflow Tuple and this is an attempt to solve some
of the problems associated with frequently updated tables. This
design optimizes the updates when none of the index columns are
modified and length of the tuple remains the same after update. In this
particular case, the updated tuple is stored in a separate overflow
relation and pulled-back into the main relation when the tuple in
the main relation becomes dead."
--
Selena Deckelmann
PDXPUG - Portland PostgreSQL Users Group
http://pugs.postgresql.org/pdx
http://www.postgresqlconference.org