[CentOS-devel] Upgrading postgresql (Re: CentOS/RHEL 5.3)

Thu Jan 22 17:25:30 UTC 2009
Les Mikesell <lesmikesell at gmail.com>

Joshua Kramer wrote:
> Any major database version upgrade requires the attention of a qualified 
> DBA who knows how to test data and applications against the new DB 
> version, and then dump/upgrade/restore.
> For example, PostgreSQL introduced some minor syntactical differences with 
> 8.3.  If your application uses the features affected by these changes, it 
> would be impossible to simply 'dump/restore' without some massaging of the 
> data and the application.
> PostgreSQL does ship with a dumper, pg_dump.  If you have the current 
> version of postmaster, then you use pg_dump to connect to that and dump 
> your data in a version-agnostic format.  IMHO, the effort of writing a 
> standalone dumper that can recognize all the old file formats is not worth 
> it, because it is a mistake to delete the old version of postmaster off 
> your system before you've done a dump of the database.

So how do you package such a thing in RPM so it can permit both new and 
old instances to run simultaneously while you do all of this required 
testing?  I suppose these days virtualbox is an almost-reasonable answer 
but it just seems wrong to have a system that by design doesn't let you 
test a new instance before replacing the old one.

   Les Mikesell
     lesmikesell at gmail.com