check_function_bodies

A configuration parameter controlling the validation of the function body string on creation

Normally the body of a function being created is validated:

postgres=# CREATE FUNCTION foo()
  RETURNS INT
  LANGUAGE SQL
AS 'SELECT * FROM bar()';
ERROR:  function bar() does not exist
LINE 4: AS 'SELECT * FROM bar()';
                          ^
HINT:  No function matches the given name and argument types. You might need to add explicit type casts.

However, if check_function_bodies is set to off, the function can be created:

postgres=# SHOW check_function_bodies;
 check_function_bodies 
-----------------------
 off
(1 row)

postgres=# \df
                       List of functions
 Schema | Name | Result data type | Argument data types | Type 
--------+------+------------------+---------------------+------
(0 rows)

postgres=# CREATE FUNCTION foo()
  RETURNS INT
  LANGUAGE SQL
AS 'SELECT * FROM bar()';
CREATE FUNCTION

Until the missing function is added, the function will of coursel fail with an ERROR:

postgres=# SELECT * FROM foo();
ERROR:  function bar() does not exist
LINE 1: SELECT * FROM bar()
                      ^
HINT:  No function matches the given name and argument types. You might need to add explicit type casts.
QUERY:  SELECT * FROM bar()
CONTEXT:  SQL function "foo" during inlining

• PostgreSQL documentation: check_function_bodies

DDL, Functions and procedures, GUC configuration item