DROP USER
Name
DROP USER -- remove a database role
Synopsis
DROP USER [ IF EXISTS ] name [, ...]
Description
Note: The following description applies both to Postgres-XC and PostgreSQL if not described explicitly.
   DROP USER is now an alias for
   DROP ROLE.
  
Compatibility
   The DROP USER statement is a
   Postgres-XC extension.  The SQL standard
   leaves the definition of users to the implementation.