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 |
Views: | Raw Message | Whole Thread | Download mbox | Resend email |
Thread: | |
Lists: | pgsql-hackers pgsql-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
From | Date | Subject | |
---|---|---|---|
Next Message | Bruce Momjian | 2007-02-20 14:51:50 | Re: [HACKERS] HOT WIP Patch - version 2 |
Previous Message | Bruce Momjian | 2007-02-20 14:43:44 | Re: [HACKERS] HOT WIP Patch - version 2 |
From | Date | Subject | |
---|---|---|---|
Next Message | Pavel Stehule | 2007-02-20 14:51:28 | Re: correct format for date, time, timestamp for XML functionality |
Previous Message | Bruce Momjian | 2007-02-20 14:43:44 | Re: [HACKERS] HOT WIP Patch - version 2 |