Usage privileges for user-defined types

To control who can use an opaque type, distinct type, or named row type, specify the Usage privilege on the data type. The Usage privilege allows the DBA or owner of the type to restrict a user's ability to assign a data type to a column, program variable (or table or view for a named row type), or assign a cast to the data type. The Usage privilege is granted to PUBLIC automatically when a data type is created (except in ANSI-compliant databases). In an ANSI-compliant database, the Usage privilege on a data type is granted to the owner of the data type.

To limit who can use an opaque, distinct, or named row type, you must first revoke the Usage privilege for PUBLIC and then specify the names of the users to whom you want to grant the Usage privilege. For example, to limit the use of a data type named circle to a group of users, you might execute the following statements:

REVOKE USAGE ON circle
   FROM PUBLIC;

GRANT USAGE ON circle
   TO dawns, stevep, terryk, camber;