Tom Lane wrote:
> "Raymond O'Donnell" <rod@iol.ie> writes:
> > On 16/12/2009 15:01, Richard Broersma wrote:
> >> It looks like the future 8.5 release will be able to
> >> preform an in-place upgrade on 8.4.
>
> > Really? That would be *wonderful*. I know it's impossible to be
> > definitive, but how likely would you say this is?
>
> It's wishful thinking. We tried to have that for 8.4, and failed: there
> are so many constraints on pg_upgrade that it's not a usable mainstream
> solution. So far as I've seen there has been no work done that would
> make it any more reliable for 8.5.
Some people just enjoy discouraging people.
pg_migrator (not pg_upgrade) has been used by many people to migrate
from 8.3 to 8.4. I just helped someone yesterday with a migration.
pg_migrator threw an error because they had reindexed pg_largeobject,
and pg_migrator was not prepared to handle that. They also had an old
cluster with a higher autovacuum_freeze_max_age than the new cluster,
causing autovacuum freeze to run during the upgrade and remove clog
files. These are unusual cases, so I assume there are many people who
successfully use pg_migrator that I never hear from.
Both of these issues are fixed in pg_migrator 8.4.6, released yesterday.
I also talked to Alvaro about using fixed oids to remove these migration
restrictions in 8.5:
o a user-defined composite data type
o a user-defined array data type
o a user-defined enum data type
So, pg_migrator is a work in progress. It current requires migration
testing and should be used by experienced Postgres users. Someday
pg_migrator will be easier to use and more reliable.
--
Bruce Momjian <bruce@momjian.us> http://momjian.us
EnterpriseDB http://enterprisedb.com
+ If your life is a hard drive, Christ can be your backup. +
