>Do I save disk space by having them as NULL instead of FALSE? So my >>application would have conditional code for NULL and TRUE, instead of >FALSE >and TRUE.
The short answer: do not even think about it. NULL has a well defined meaning within SQL: "we do not know the value", with "well defined" being something totally different from "intuitive". With "using NULL as false" you woud get: select whatever from yourtable where not (booleancolumn = true ) would result in ....wait for it .... zero rows. Because "NULL" is not "not =" to true. There is no potential diskspace saving in the world that could be worth those troubles. Harald -- Harald Armin Massa www.2ndQuadrant.de PostgreSQL Training, Services and Support 2ndQuadrant Deutschland GmbH GF: Harald Armin Massa Amtsgericht Stuttgart, HRB 736399 -- Sent via pgsql-general mailing list (pgsql-general@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general