Skip site navigation (1) Skip section navigation (2)

Re: pre-algebra discussion - HOT?

From: Jeff Davis <pgsql(at)j-davis(dot)com>
To: Rich Shepard <rshepard(at)appl-ecosys(dot)com>
Cc: pdxpug(at)postgresql(dot)org
Subject: Re: pre-algebra discussion - HOT?
Date: 2007-09-20 21:10:18
Message-ID: 1190322618.5943.80.camel@dogma.ljc.laika.com (view raw or flat)
Thread:
Lists: pdxpug
On Thu, 2007-09-20 at 13:22 -0700, Rich Shepard 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.
> 

HOT stands for Heap Only Tuple, and refers to a an updated version of a
tuple that shares the index entry with the original version of the
tuple. This only works for UPDATEs which do not change any indexed
columns, but it allows retail (page-at-a-time) space reclamation
(VACUUM) which drastically reduces table and index bloat and improves
efficiency under heavy UPDATE load.

Regards,
	Jeff Davis


In response to

pdxpug by date

Next:From: Jeff DavisDate: 2007-09-20 21:25:13
Subject: Re: pre-algebra discussion - HOT?
Previous:From: Selena DeckelmannDate: 2007-09-20 20:57:21
Subject: Re: pre-algebra discussion - HOT?

Privacy Policy | About PostgreSQL
Copyright © 1996-2014 The PostgreSQL Global Development Group