SQL::Statement is under heavy development and we've been adding support for a variety of SQL features with each major release. The development versions are available at an SVN repository and I'll be creating a kwiki to discuss development soon as there are already several other developers working on it with me. I would very much welcome any suggestion for improvements and even more co-developers. The most recent version on CPAN includes all new POD on how to extend the SQL syntax via SQL, e.g. the newly introduced CREATE TYPE, DROP TYPE commands allow you to allow and disallow types in any way you'd like.