dbms_lock.sleep must be declared error ( Packages Invalid ) solution

Hello, n the Oracle PL/SQL, I want to test the sleep function. I am using PHM_DEV schema. but it gives me error : dbms_lock.sleep must be declared error Schema name : PHM_DEV Cause :The Oracle schema  does not have access to the DBMS_LOCK package. solutions : connect to database ass sysdba grant execute on SYS.DBMS_LOCK to schema_name; […]