On Tue, 2002-07-09 at 17:49, Oliver Elphick wrote: > On Tue, 2002-07-09 at 16:41, Hannu Krosing wrote: > > On Tue, 2002-07-09 at 13:48, Oliver Elphick wrote: > > > On Tue, 2002-07-09 at 01:30, Matthew T. O'Connor wrote: > > > > Example: When PG 7.3 is released, the RPM / deb / setup.exe include the > > > > postmaster binary for v 7.2 (perhaps two or three older versions...). > > > > > > That isn't usable for Debian. A package must be buildable from source; > > > so I would have to include separate (though possibly cut-down) source > > > for n previous packages. It's a horrid prospect and a dreadful kludge > > > of a solution - a maintainer's nightmare. > > > > The old postmaster should not be built/distributed. As it is for > > _upgrading_ only, you just have to _keep_ it when doing an upgrade, not > > build a new "old" one ;) > > No, it doesn't work like that. You cannot rely on anything's being left > from an old distribution; apt is quite likely to delete it altogether > before installing the new version (to enable dependencies to be > satisfied). At present I have the preremoval script copy the old > binaries to a special location in case they will be needed, but that > fails if the version is very old (and doesn't contain that code), and > it's a very fragile mechanism. > > I never have understood why the basic table structure changes so much > that it can't be read; just what is involved in getting the ability to > read old versions?
The big change was from 6.x to 7.x where a chunk of data moved from end of page to start of page and tableoid column was added. Otherways the table structure is quite simple. The difficulties with user _data_ can be mainly because of binary format changes for some types and such. But I still can't see how will having a binary dumper that does mostly the work of [ old_backend -c "COPY tablex TO STDOUT" ] help us here. IIRC the main difficulties in upgrading have always been elsewhere, like migrating always changing system table data. ---------- Hannu ---------------------------(end of broadcast)--------------------------- TIP 5: Have you checked our extensive FAQ? http://www.postgresql.org/users-lounge/docs/faq.html
