New security enhancement has been introduced in Oracle 12c that will implement “white listing” on the PL/SQL code that will provide an isolation level.

The new keyword ACCESSIBLE BY can be used with the following database objects only:  function, package, procedure, and type.

To illustrate… I have created the following 2 packages under DUMMY_TEST schema:

CREATE OR REPLACE PACKAGE dummy1_pkg

IS

PROCEDURE do_action1;

END;

/

CREATE OR REPLACE PACKAGE BODY dummy1_pkg

IS

PROCEDURE do_action1

IS

BEGIN

dummy2_pkg.do_action2;

dummy2_pkg.do_action3;

END;

END;

/

 

CREATE OR REPLACE PACKAGE dummy_test.dummy2_pkg  

ACCESSIBLE BY (dummy1_pkg)

IS

PROCEDURE do_action2;

 

PROCEDURE do_action3;

END;

/

 

CREATE OR REPLACE PACKAGE BODY

dummy2_pkg

IS

PROCEDURE do_action2

IS

BEGIN

DBMS_OUTPUT.put_line (‘Hi Action 2’);

END;

 

PROCEDURE do_action3

IS

BEGIN

DBMS_OUTPUT.put_line (‘Hi Action 3’);

END;

END;

/

 

I was able to execute dummy1 package with no problems as shown below, by executing:

BEGIN

dummy1_pkg.do_action1;

END;

/

 

When I try to directly execute the other package dummy2_pckg by executing the query:

BEGIN

dummy2_pkg.do_action2;

END;

/

The following error is thrown: PLS-00904: insufficient privilege to access object DUMMY2_PKG

Remark: you can specify a package or a procedure in the accessible by clause while even if this package/procedure is not yet created, so you will not face any errors at compilation time.