Cross Database Links

I think I read somewhere that you CANNOT access a table view etc. in another
database.
I wanted to confirm that this was the case or see if there was a method
(hack) to create
an alias to another database.

For example:

psql foo
foo# CREATE VIEW v1 AS SELECT * FROM BAR.t1;

where BAR is another database (same PostgreSQL server).

I was also wondering what the correct method is for restircting users
ability to
create tables, views etc.