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

Re: [HACKERS] HOT WIP Patch - version 2

From: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
To: Bruce Momjian <bruce(at)momjian(dot)us>
Cc: Pavan Deolasee <pavan(dot)deolasee(at)gmail(dot)com>, PostgreSQL-development <pgsql-hackers(at)postgresql(dot)org>, pgsql-patches(at)postgresql(dot)org
Subject: Re: [HACKERS] HOT WIP Patch - version 2
Date: 2007-02-20 14:50:40
Message-ID: 26769.1171983040@sss.pgh.pa.us (view raw or flat)
Thread:
Lists: pgsql-hackerspgsql-patches
Bruce Momjian <bruce(at)momjian(dot)us> writes:
> Pavan Deolasee wrote:
>> When following a HOT-update chain from the index fetch, if we notice that
>> the root tuple is dead and it is HOT-updated, we try to prune the chain to
>> the smallest possible length. To do that, the share lock is upgraded to an
>> exclusive lock and the tuple chain is followed till we find a
>> live/recently-dead
>> tuple. At that point, the root t_ctid is made point to that tuple. In order

> I assume you meant recently-dead here, rather than live/recently-dead,
> because we aren't going to change live ctids, right?

"Recently dead" means "still live to somebody", so those tids better not
change either.  But I don't think that's what he meant.  I'm more
worried about the deadlock possibilities inherent in trying to upgrade a
buffer lock.  We do not have deadlock detection for LWLocks.

			regards, tom lane

In response to

Responses

pgsql-hackers by date

Next:From: Bruce MomjianDate: 2007-02-20 14:51:50
Subject: Re: [HACKERS] HOT WIP Patch - version 2
Previous:From: Bruce MomjianDate: 2007-02-20 14:43:44
Subject: Re: [HACKERS] HOT WIP Patch - version 2

pgsql-patches by date

Next:From: Pavel StehuleDate: 2007-02-20 14:51:28
Subject: Re: correct format for date, time, timestamp for XML functionality
Previous:From: Bruce MomjianDate: 2007-02-20 14:43:44
Subject: Re: [HACKERS] HOT WIP Patch - version 2

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