"Clustering"

The heading "Multi-Master Replication Using Clustering" doesn't make
sense to me.  Clustering is bunching more than host together to achieve
a common goal.  Thus multimaster replication may be a way to achieve
clustering, but clustering is not a way to achieve multimaster
replication.  I don't actually see clustering defined in the
documentation.  Can someone explain the categorization?

(FWIW, I think "Clustering For Parallel Query Execution" later in the
list is an appropriate use of the term.)

--
Peter Eisentraut
http://developer.postgresql.org/~petere/