Permanent alias for postgresql table

Hi list,

I'm searching for a way to create permanent alias for
tablenames in postgresql. We are storing various versions
of a routable network in postgresql (postgis, pgrouting)
and access a certain version with a bunch of php-skripts.
We like to use aliases for the "currently used tables" oo
be able to relink the current tables rapidly by changing
the alias target.

Any idea - or is this approach nonsense?

Marco