Re: HOT for PostgreSQL 8.3 - Mailing list pgsql-hackers

From Joshua D. Drake
Subject Re: HOT for PostgreSQL 8.3
Date
Msg-id 45CA3D4E.4050309@commandprompt.com
Whole thread Raw
In response to HOT for PostgreSQL 8.3  ("Simon Riggs" <simon@2ndquadrant.com>)
Responses Re: HOT for PostgreSQL 8.3  ("Merlin Moncure" <mmoncure@gmail.com>)
List pgsql-hackers
Simon Riggs wrote:
> Heap Only Tuples ("HOT") is a simplification of earlier proposals for
> improving the way the server handles frequent updates, based upon what's
> been learned and feedback received.
> 
> Heap Only Tuples
> ----------------
> 
> The basic idea is that when a tuple is UPDATEd we can, in certain
> circumstances, avoid inserting index tuples for a tuple. Such tuples are
> marked HEAP_ONLY_TUPLE, but their storage is otherwise identical to
> other tuples. The pre-conditions for allowing a HOT UPDATE are
> - UPDATE doesn't change any indexed columns

Uhmmm... how often is that the case? Don't get me wrong, bravo but that
seems a rather large limitation.

Considering it, this would certainly be a boon in web space where you
have things like Rails doing:

UPDATE foo SET first_name = 'Barney' WHERE id = 1;

That would qualify correct?

Sincerely,

Joshua D. Drake


-- 
     === The PostgreSQL Company: Command Prompt, Inc. ===
Sales/Support: +1.503.667.4564 || 24x7/Emergency: +1.800.492.2240
Providing the most comprehensive  PostgreSQL solutions since 1997            http://www.commandprompt.com/

Donate to the PostgreSQL Project: http://www.postgresql.org/about/donate
PostgreSQL Replication: http://www.commandprompt.com/products/



pgsql-hackers by date:

Previous
From: "Simon Riggs"
Date:
Subject: Re: HOT for PostgreSQL 8.3
Next
From: "Merlin Moncure"
Date:
Subject: Re: HOT for PostgreSQL 8.3