Обсуждение: maximum number of rows in table - what about oid limits?

postgresql docs claim an essentially unlimited number of
rows per table.

   http://postgresql.crimelabs.net/users-lounge/limitations.html

this doesn't make sense if each row has an oid.
do more subtle side effects exist if the oid wraps?

thanks - jmscottJUSTREMOVEME@yahoo.com