Re: Upgrading rant.

On Friday 03 January 2003 18:31, Bruce Momjian wrote:
> Tom Lane wrote:
> > There isn't any fundamental reason why we cannot have a pg_upgrade
> > utility; claiming that there is something wrong with how we handle
> > catalog changes misses the point. The point is that *someone would
> > have to do the work*. Unless someone wants to step up and volunteer,
> > there's little value in discussing it.

> pg_upgrade does work, assuming there are no changes to the index or heap
> file formats. (However, I now need to update it for schemas.) However,
> the last time I worked on it for 7.2, no one was really interested in
> testing it, so it never got done. In fact, there was a bug in the
> handling of clog or wal files, but I didn't find out about it until long
> after 7.2 because no one was using it.

> Is pg_upgrade too hard to run? Is no one really interested in it?

It has been considered 'experimental' in the past, Bruce. It needs more
credibility from the development group, as in 'We recommend you try to use
pg_upgrade (after making a backup), then attempt to do a dump/restore if
pg_upgrade doesn't work" (and pg_upgrade needs to be more robust in its
failure modes).

I am very interested in pg_upgrade, as I believe I mentioned the last go
through this topic. But it's the 'red-headed stepchild' utility here. (I'm
red-headed, my mother's red-headed, so no slight meant to those of fiery
folicles.) But it's also all or nothing -- you go the whole way through.

It's again our tremendous dependence upon the contents of the system catalogs
that does us in. That is one of our greatest strengths, until you have to
upgrade for some reason. Then it becomes our biggest liability.

And unlike Tom I think it is worthwhile to discuss it periodically, to remind
the group as a whole (which composition and membership changes frequently)
that there's a problem waiting to be solved.
--
Lamar Owen
WGCR Internet Radio
1 Peter 4:11