Could we modify the Relation structure to hold an Oid counter? So every where
Postgres calls "newoid(void)" it gets changed to pass the relation structure it
will be associated with, i.e. newoid(Relation *). That way, every relation
could have its own counter, AND perhaps its own spinlock. Relations are shared
amongst the various processes, correct? If you pass NULL as the relation, you
get an OID out of the ShmemVariableCache->nextXid.
Am I being overly simplistic?
