def grant_default_usage_install_privileges(cls, cur, schema_name, roles):
        """
        Sets search path
        """
        cur.execute('ALTER DEFAULT PRIVILEGES IN SCHEMA {0} '
                    'GRANT SELECT, INSERT, UPDATE, DELETE ON TABLES TO {1};'
                    'ALTER DEFAULT PRIVILEGES IN SCHEMA {0} GRANT EXECUTE ON FUNCTIONS TO {1};'
                    'ALTER DEFAULT PRIVILEGES IN SCHEMA {0} '
                    'GRANT USAGE, SELECT ON SEQUENCES TO {1};'
                    .format(schema_name, roles))