isolating users from each other

Hello,

I'm setting up a PostgreSQL installation accessible by many different
users. The layout is:
- all users connect to the same database
- every user has its own schema, no write access to the public schema
- by default no additional privileges for the users

Thus, a user cannot access the data (e. g. contents of a table) of
another user. But a user can see all metadata (names of objects, layout
of tables, definitions of views, ...) of all other users. Is there any
possibility to restrict access to other users metadata? (I tried to
revoke access privileges on the pg_catalog schema, but then a user can
no longer access his own metadata ...)

Thanks in advance,
Christian

--
Dr. Christian Rank
Rechenzentrum Universität Passau
Innstr. 33
D-94032 Passau
GERMANY
Tel.: 0851/509-1838
Fax: 0851/509-1802
PGP public key see http://www.rz.uni-passau.de/mitarbeiter/rank