Re: SE-PostgreSQL and row level security

Martijn van Oosterhout <kleptog@svana.org> writes:
> One thing I keep missing in this discussion: the term "row-level
> security" in the above senstence in not the important part. Right now
> you can revoke SELECT permission on a table with a foreign key and it
> will still prevent UPDATEs and DELETEs of the primary key, allowing
> users to infer the existance of an invisible FK.

> This is the same "covert channel", so why is it a problem for
> SE-Postgres and not for normal Postgres?

The reason it's a problem for SE-Postgres is that the entire row-level
security feature is advertised on the premise that it allows you to
hide the existence of data; a claim not made by regular SQL.  If the
feature doesn't do what it's claimed to do then it's fair to ask why
have it.
        regards, tom lane