Pa ne bas, ne citas man page koji sam ti napisao da pogledas...
pg_dumpall also dumps global objects that are common to all
databases. (pg_dump does not save these objects.) This currently
includes information about database users and groups, and access per‐
missions that apply to databases as a whole.
Btw. evo citata iz fajla /usr/share/doc/packages/postgresql/README.SuSE.en kod SUSE linuxa, na koji se poziva kad se upgrade-uje baza...
Before updating PostgreSQL packages whose version numbers are to
increase by at least the second decimal place or higher (for example,
6.4.x to 7.0.x or 7.1.x to 7.2.x), use the pg_dumpall program to back
up your PostgreSQL databases. A typical command for doing this is:
pg_dumpall > SAVE
Backups should be performed as user "postgres". Once the backup is
completed successfully, shut down the PostgreSQL server (as root:
"rcpostgresql stop"). Further configuration files in
/var/lib/pgsql/data, including pg_hba.conf and postgresql.conf,
may need to be backed up as well.
Afterwards, delete the previous database files
rm -r /var/lib/pgsql/data/*
or, if you have enough space, move it to
mv /var/lib/pgsql/data /var/lib/pgsql/data.old
so that the new database structure can be created under
/var/lib/pgsql/data when you start the new database server for the
first time (as root:"rcpostgresql start").
The saved contents of the database and the configuration files will
then have to be played back as user postgres:
psql template1 -f SAVE
If, following exhaustive testing, you are certain that everything is
still available and functioning properly after the migration, delete
the backup file and the old database files.