--change to signature mode

ALTER SESSION SET REMOTE_DEPENDENCIES_MODE = 'SIGNATURE'

--first setup

CREATE OR REPLACE PACKAGE referenced_pkg IS 
  PROCEDURE referenced_procedure (pi_value IN number); 
END; 

CREATE OR REPLACE PACKAGE BODY referenced_pkg IS 
  PROCEDURE referenced_procedure (pi_value IN number) IS 
  BEGIN 
    dbms_output.put_line('referenced_procedure'); 
  END; 
END; 

CREATE OR REPLACE PROCEDURE dependent_procedure IS 
BEGIN 
  dbms_output.put_line('dependent_procedure'); 
  referenced_pkg.referenced_procedure(5); 
END; 

--all objects are valid

SELECT OBJECT_NAME, OBJECT_TYPE, STATUS 
  FROM USER_OBJECTS 
 WHERE OBJECT_NAME IN ('DEPENDENT_PROCEDURE', 'REFERENCED_PKG')

BEGIN 
  dbms_output.put_line('start'); 
  dependent_procedure; 
  dbms_output.put_line('end'); 
  dbms_output.put_line('-----------------------'); 
END; 

--change the data type of a parameter to another data type in the same class (from 'number' to 'integer')

CREATE OR REPLACE PACKAGE referenced_pkg IS 
  PROCEDURE referenced_procedure (pi_value IN integer); 
END; 

CREATE OR REPLACE PACKAGE BODY referenced_pkg IS 
  PROCEDURE referenced_procedure (pi_value IN integer) IS 
  BEGIN 
    dbms_output.put_line('referenced_procedure'); 
  END; 
END; 

--the dependent_procedure got invalid although the Oracle documentation says: 'Changing the data type of a parameter to another data type in the same class does not change the RPC signature, but changing the data type to a data type in another class does.

SELECT OBJECT_NAME, OBJECT_TYPE, STATUS 
  FROM USER_OBJECTS 
 WHERE OBJECT_NAME IN ('DEPENDENT_PROCEDURE', 'REFERENCED_PKG')