The DROP TYPE statement removes the specified user-defined type (UDT).
A UDT is created by a CREATE TYPE statement.
DROP TYPE typeName RESTRICT
The RESTRICT keyword is required. CASCADE semantics are not supported. That is, Derby will not track down and drop orphaned objects.
Dropping a UDT implicitly drops all USAGE privileges that reference it.
You cannot drop a type if it would make another SQL object unusable. This includes the following restrictions:
DROP TYPE price RESTRICT;