Bill Moran <wmoran@potentialtech.com> writes:
> To clarify my earlier comments, if you're going to use pg_upgrade, you
> probably won't need to downgrade to 8.4. My comments about putting
> 8.4 back on would have be necessary if you were going to go the old
> dump/restore route.
Note that pg_upgrade depends on having a copy of the old postmaster
executable available (so that it can read the old catalogs). If you're
using a pre-packaged version then hopefully the packager took care of
that for you, but if you're trying to build from source then it's
something you'll have to deal with.
regards, tom lane