Re: Versioning policy and pg_upgrade - Mailing list pgsql-www

Joshua D. Drake wrote:
> On Mon, 2010-08-16 at 13:59 +0100, Thom Brown wrote:
>
> > But I propose expanding it to read:
> >
> > "Major releases usually change the internal format of system tables
> > and data files. These changes are often complex, so we don't maintain
> > backward compatibility for data files. A dump/reload of the database
> > cluster is required for major upgrades for upgrading from 8.2 or
> > earlier.  For upgrading from version 8.3 and later, there is the
> > option to use pg_upgrade (also known as pg_migrator prior to version
> > 9.0), capable of in-place upgrades.  This means, for example, you can
> > upgrade any minor version of 8.3 to 8.4 without having to perform a
> > full backup and restore, resulting in a significantly faster upgrade."
> >
> > Too wordy?
>
> Yes :D (well I think so):
>
> "A Major release changes the internal data format of the cluster.
> Due to this change a dump/reload of the cluster is required for major
> upgrades for upgrading from 8.2 or earlier.
>
> If upgrading from version 8.3 and later, certain installs may be able to
> use pg_upgrade (previously named pg_migrator). If pg_upgrade is
> compatible with your cluster (see the docs) you will able to perform an
> in-place upgrades. Although downtime is still required, this is much
> quicker than a dump/restore."

Based on this discussion from August, I suggest the following patch be
applied to versioning.html.  It mentions pg_upgrade as an major upgrade
option and links to the pg_upgrade page that has all the details.

--
  Bruce Momjian  <bruce@momjian.us>        http://momjian.us
  EnterpriseDB                             http://enterprisedb.com

  + It's impossible for everything to be true. +
*** ./versioning.html.orig    Fri Jan 28 10:50:25 2011
--- ./versioning.html    Fri Jan 28 11:22:17 2011
***************
*** 13,19 ****
  </p>

  <p>
! Major releases usually change the internal format of system tables and data files.  These changes are often complex,
sowe don't maintain backward compatibility for data files.  A dump/reload of the database is required for major
upgrades.
  </p>

  <p>
--- 13,19 ----
  </p>

  <p>
! Major releases usually change the internal format of system tables and data files.  These changes are often complex,
sowe do not maintain backward compatibility of all stored data.  A dump/reload of the database or use of the <a
href="http://www.postgresql.org/docs/current/static/pgupgrade.html">pg_upgrade</a>module is required for major
upgrades.
  </p>

  <p>