Re: Updates of SE-PostgreSQL 8.4devel patches (r1197)

On Fri, 2008-11-07 at 13:19 -0500, Bruce Momjian wrote:
> The security context on each row could be an optional column present
> > only if HEAP_HASSECURITYCONTEXT is set (0x0010 see htup.h), just
> like
> > OIDs. Use a specific datatype rather than TEXT. That datatype could
> be
> > an identifier to pg_security. Security people have big databases
> too, so
> > we need to compress the security context more and take out parse
> time of
> > string handling. Don't think we should use Oids, they're too big.
> Might
> > be easier to use a 2byte field and restrict access to 32,000
> contexts,
> > which is easily enough. TEXT also makes me nervous, just in case
> there
> > is some collation/encoding weirdness that allows contexts to be
> > subverted. Fixed integers are hard to compromise in that respect.
> 
> I think the security mechanism is more complex than just assigning a
> single security identifier, but perhaps not; I am unsure.

Maybe. We already handle such complexity for comboids and multixacts, so
I suggest we do the same thing here.

Any system with more than 32,000 security contexts is going to be
unmanageable and probably therefore insecure...

-- Simon Riggs           www.2ndQuadrant.comPostgreSQL Training, Services and Support