From: | Andres Freund <andres(at)anarazel(dot)de> |
---|---|
To: | Simon Riggs <simon(at)2ndQuadrant(dot)com> |
Cc: | Alvaro Herrera <alvherre(at)alvh(dot)no-ip(dot)org>, pgsql-committers <pgsql-committers(at)postgresql(dot)org> |
Subject: | Re: pgsql: Implement ALTER TABLE .. SET LOGGED / UNLOGGED |
Date: | 2014-08-23 16:47:47 |
Message-ID: | 20140823164747.GA5779@awork2.anarazel.de |
Views: | Raw Message | Whole Thread | Download mbox | Resend email |
Thread: | |
Lists: | pgsql-committers |
On 2014-08-23 17:28:38 +0100, Simon Riggs wrote:
> On 23 August 2014 14:57, Andres Freund <andres(at)anarazel(dot)de> wrote:
> > On August 23, 2014 3:49:32 PM CEST, Simon Riggs <simon(at)2ndQuadrant(dot)com> wrote:
> >>On 22 August 2014 19:30, Alvaro Herrera <alvherre(at)alvh(dot)no-ip(dot)org>
> >>wrote:
> >>
> >>> Implement ALTER TABLE .. SET LOGGED / UNLOGGED
> >>>
>
> >>When moving from unlogged to logged, where do we remove the init fork?
> >>
> >>Couldn't see the keywords fork or init anywhere in the patch, so maybe
> >>its hidden somewhere.
> >
> > A new relfilenode is filled with the data - the old one, including the init fork, gets removed by the normal mechanics of rewriting rels.
>
> Why do we do that? Table rewrite takes hours.
There was a long thread about it on -hackers. Doing it without a rewrite
and without loosing transactional semantics is really rather hard. And
having the capability of doing it with a rewrite is better than not
having it at all.
Greetings,
Andres Freund
--
Andres Freund http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Training & Services
From | Date | Subject | |
---|---|---|---|
Next Message | Andrew Dunstan | 2014-08-23 20:03:28 | Re: pgsql: Implement ALTER TABLE .. SET LOGGED / UNLOGGED |
Previous Message | Simon Riggs | 2014-08-23 16:28:38 | Re: pgsql: Implement ALTER TABLE .. SET LOGGED / UNLOGGED |