Not sure if term "singleton" is valid in relation database.
The term is valid in mathematics: The relational model is an extension of set theory, eg the algebra includes set operators such as union, intersection, difference... In the set theory, a singleton designate is a exactly-one-element set. At least Wikipedia and my dwindling memories tell me so:-)
-- Fabien. -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
