Tom Lane wrote: > Andrew Dunstan <and...@dunslane.net> writes: > > I think it's a lot more nebulous than that. At the same time I think the > > days when we can blithely change the on-disk format with hardly a > > thought for migration are over. IOW, there's agreement things have to > > change, but the exact shape of the change is not yet clear (at least to > > me) ;-) > > Yeah. I think we're going to start paying more than zero attention to > this, but we don't yet have a handle on what the real parameters are. > In particular, it's hard to argue that pg_migrator has yet achieved > more than experimental status, so accepting or rejecting patches on > the grounds of whether they would or would not break pg_migrator might > be a bit premature. And at the other end of the spectrum, nobody except > Zdenek wants to deal with changes as invasive as the ones he's proposed. > So we're still feeling our way here. We do *not* have a framework in > which someone could submit a patch that includes an on-disk migration > aspect, so David's position that we should immediately institute a > hard requirement for such seems a bit ivory-tower. We might as well > just say that the on-disk format is frozen, because that's what the > effect would be. > > But having said all that, I'm okay with a go-slow position on on-disk > changes for the next little while. That would give us some breathing > room to see if something like pg_migrator is really workable at all. > We need to find out just how far that approach goes before we can make > many decisions in this area.
I would be happy if we can just allow pg_migrator to _detect_ incompatible changes, and that nothing _major_ changes between releases that pg_migrator can't fix (we fixed the sequence changes in 8.4). /contrib changes are part of the first group, so I am happy to know about them and detect them; changing the tuple format, on the other hand, could make pg_migrator useless. -- Bruce Momjian <br...@momjian.us> http://momjian.us EnterpriseDB http://enterprisedb.com + If your life is a hard drive, Christ can be your backup. + -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
