Getting acces to MVCC version number

Hi all developpers,

This is just a idea.

How about making available the MVCC last version number just like oid is
available. This would simplify a lot of table design. You know, having
to add a field "updated::timestamp" to detect when a record was updated
while viewing it (a la pgaccess).

That way, if the version number do not match, one would know that the
reccord was updated since last retrieved.

What do think?

JLL