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

Re: Not HOT enough

From: Pavan Deolasee <pavan(dot)deolasee(at)gmail(dot)com>
To: Simon Riggs <simon(at)2ndquadrant(dot)com>
Cc: Alvaro Herrera <alvherre(at)commandprompt(dot)com>, Robert Haas <robertmhaas(at)gmail(dot)com>, Pg Hackers <pgsql-hackers(at)postgresql(dot)org>
Subject: Re: Not HOT enough
Date: 2011-11-23 17:07:11
Message-ID: (view raw, whole thread or download thread mbox)
Lists: pgsql-hackers
On Wed, Nov 23, 2011 at 9:44 PM, Simon Riggs <simon(at)2ndquadrant(dot)com> wrote:
> On Wed, Nov 23, 2011 at 3:20 PM, Alvaro Herrera
> <alvherre(at)commandprompt(dot)com> wrote:
>> Excerpts from Robert Haas's message of mié nov 23 12:15:55 -0300 2011:
>>> > And it effects shared catalogs only, which are all low traffic anyway.
>>> I think "low traffic" is the key point.  I understand that you're not
>>> changing the VACUUM behavior, but you are making heap_page_prune_opt()
>>> not do anything when a shared catalog is involved.  That would be
>>> unacceptable if we expected shared catalogs to be updated frequently,
>>> either now or in the future, but I guess we don't expect that.
>> Maybe not pg_database or pg_tablespace and such, but I'm not so sure
>> about pg_shdepend.  (Do we record pg_shdepend entries for temp tables?)
> Normal catalog access does not use HOT and never has.

I don't understand that. We started with the simplified assumption
that HOT can skip catalog tables, but later that was one of the
pre-conditions Tom spelled out to accept HOT patch because his view
was if this does not work for system tables, it probably does not work
at all.


Pavan Deolasee

In response to

pgsql-hackers by date

Next:From: Simon RiggsDate: 2011-11-23 17:58:25
Subject: Re: Not HOT enough
Previous:From: Tom LaneDate: 2011-11-23 17:01:40
Subject: Re: Not HOT enough

Privacy Policy | About PostgreSQL
Copyright © 1996-2017 The PostgreSQL Global Development Group