> As far as the page not fitting after conversion, what about some user
> command that will convert an entire table to the new format if page
> expansion fails.
Having to run a manual command defeats the purpose somewhat, though.
Especially if you have no way of knowing on what tables it needs to be
> I am ready to focus on these issues for 8.4; all this needs to be
> fleshed out, perhaps on a wiki. As a starting point, what would be
> really nice is to start a wiki that lists all data format changes for
> every major release.
Have you looked at http://wiki.postgresql.org/wiki/In-place_upgrade
already, that Greg Smith mentioned elsewhere in this thread? That's a
good starting point.
In fact, I don't think there's any low-level data format changes yet
between 8.3 and 8.4, so this would be a comparatively easy release to
implement upgrade-in-place. There's just the catalog changes, but AFAICS
nothing that would require scanning through relations.