DROP LANGUAGE removes the definition of a previously registered procedural language. You must be a superuser or the owner of the language to use DROP LANGUAGE.
Note: As of PostgreSQL 9.1, most procedural languages have been made into "extensions", and should therefore be removed with DROP EXTENSION not DROP LANGUAGE.
Do not throw an error if the language does not exist. A notice is issued in this case.
The name of an existing procedural language. For backward compatibility, the name can be enclosed by single quotes.
Automatically drop objects that depend on the language (such as functions in the language), and in turn all objects that depend on those objects (see Section 5.13).
Refuse to drop the language if any objects depend on it. This is the default.