Re: reserving space in a rec for future update

From: Erik Jones <erik(at)myemma(dot)com>
To: Mike Charnoky <noky(at)nextbus(dot)com>
Cc: Andrew Sullivan <ajs(at)crankycanuck(dot)ca>, pgsql-general(at)postgresql(dot)org
Subject: Re: reserving space in a rec for future update
Date: 2007-11-14 17:02:48
Message-ID: AE1E3344-6BA9-4356-8401-6B8E0C39DE9B@myemma.com
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-general


On Nov 14, 2007, at 10:44 AM, Mike Charnoky wrote:

> In this usage scenario, doesn't the new HOT (heap only tuples) feature
> of PG8.3 help, in terms of the DB requiring less VACUUM maintenance?
>
> I am similarly performing a huge number of inserts, followed by a huge
> number of updates to fill in a few null fields. The data is
> indexed by
> insert time. My problem is, selects using that index degrade over
> time
> as updates are performed, presumably because data is no longer ordered
> sequentially across pages after updates are performed. I was hoping
> that HOT would help here and am actually installing PG8.3 now in order
> to perform some testing...
>
>
> Mike

Some, what HOT does is keeps index rows from being updated when
updates are made to column values that aren't indexed. The same
insert/delete still happens in the table data.

Erik Jones

Software Developer | Emma®
erik(at)myemma(dot)com
800.595.4401 or 615.292.5888
615.292.0777 (fax)

Emma helps organizations everywhere communicate & market in style.
Visit us online at http://www.myemma.com

In response to

Responses

Browse pgsql-general by date

  From Date Subject
Next Message Alvaro Herrera 2007-11-14 17:11:08 Re: reserving space in a rec for future update
Previous Message Andrew Sullivan 2007-11-14 16:54:47 Re: reserving space in a rec for future update