Oliver Fromme <olli(at)lurza(dot)secnetix(dot)de> writes:
> We have a PostgreSQL 7.3.4 cluster which is used by several
> customers. Every customer has his own database. I have
> revoked SELECT access on pg_user from the customers, because
> they should not be able to see which other customers exist
> on the cluster.
That is a bad idea (and incomplete anyway; wouldn't looking at
pg_database give the same information?)
If you really need that much separation, give each customer his own
database cluster (postmaster).
regards, tom lane