Re: upgrade postgres 7.1 to 7.4.2

On Tue, Apr 20, 2004 at 14:36:57 +0100,
  csysi <csysi@fe.up.pt> wrote:
> Hello, i upgrade postgres version 7.1 to version 7.4.2 and it tell me that
> the databases are incompatible.
>
> Can i convert the databases ?

You need to do a dump and reload to go between major releases (e.g.
from 7.1.x to 7.2.x). If you overlaid your 7.1 binaries you are going
to have to uninstall 7.4 and reinstall 7.1 and dump the database.
If you have the 7.1 binaries and the 7.4 binaries available, you
should use the 7.4 pg_dump(all) to do the dump as it is better
about handling dependencies and some other things.