DROP SCHEMA removes schemas from the database.
A schema can only be dropped by its owner or a superuser. Note that the owner can drop the schema (and thereby all contained objects) even if he does not own some of the objects within the schema.
The name of a schema.
Automatically drop objects (tables, functions, etc.) that are contained in the schema.
Refuse to drop the schema if it contains any objects. This is the default.
To remove schema mystuff from the database, along with everything it contains:
DROP SCHEMA mystuff CASCADE;
DROP SCHEMA is fully conforming with the SQL standard, except that the standard only allows one schema to be dropped per command.