Re: Renaming of pg_xlog and pg_clog

Alvaro Herrera <alvherre@2ndquadrant.com>

From: Alvaro Herrera <alvherre@2ndquadrant.com>
To: Michael Paquier <michael.paquier@gmail.com>
Cc: Andres Freund <andres@anarazel.de>, Peter Eisentraut <peter.eisentraut@2ndquadrant.com>, Tom Lane <tgl@sss.pgh.pa.us>, Magnus Hagander <magnus@hagander.net>, PostgreSQL-development <pgsql-hackers@postgresql.org>
Date: 2016-08-27T17:56:08Z
Lists: pgsql-hackers
Michael Paquier wrote:
> On Sat, Aug 27, 2016 at 6:34 AM, Andres Freund <andres@anarazel.de> wrote:
> > On 2016-08-26 17:31:14 -0400, Peter Eisentraut wrote:
> >> I agree with all that.  But the subject line is specifically about
> >> moving pg_xlog.  So if your opinion is that we shouldn't move pg_xlog,
> >> then that is noted.  But if we were to move it, we can think about a
> >> good place to move it to.
> >
> > I think it's probably worth moving pg_xlog, because the benefit also
> > includes preventing a few users from shooting themselves somewhere
> > vital. That's imo much less the case for some of the other moves.  But I
> > still don't think think a largescale reorganization is a good idea,
> > it'll just stall and nothing will happen.
> 
> OK, so let's focus only on the renaming mentioned in $subject. So far
> as I can see on this thread, here are the opinions of people who
> clearly gave one:
> - Rename them, hard break is OK: Michael P, Bruce, Stephen (depends on
> David's input),  Magnus
> - Rename them, hard break not OK: Fujii-san (perhaps do nothing?)
> - Do nothing: Simon (add a README), Tom, Peter E

I'm for renaming too, but I'd go with Peter E's suggestion: move pg_xlog
to something like $PGDATA/var/wal or $PGDATA/srv/wal or something like that.

-- 
Álvaro Herrera                http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services


Commits

  1. Rename "pg_clog" directory to "pg_xact".

  2. Improve error reporting in pg_upgrade's file copying/linking/rewriting.