Marc Lustig, 08.02.2010 11:36:
> Hi, can we safely put the data from /var/lib/postgresql/8.4/main/ of
> server x to /var/lib/postgresql/8.3/main/ of server y, considering
> that the new target machine is running 8.3 whereas the old one ran
> 8.4 ?
No, a dump & restore is required (as stated in the release notes)
You can also try pg_migrator. It was introduced with 8.4 and will upgrade the data "in-place" (i.e. without a dump and restore)
Regards
Thomas