I think I've found answer to my question http://www.commandprompt.com/blogs/joshua_drake/2009/01/fk_check_enum_or_domain_that_is_the_question/
Michal Szymanski -- Sent via pgsql-performance mailing list (pgsql-performance@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
