CREATE OR REPLACE procedure CUSTOM.BKP_cleanup AUTHID CURRENT_USER as
cursor kill_tables is
select object_name
from ALL_OBJECTS
where created < trunc(sysdate) - 30
and object_type = 'TABLE'
AND OWNER = 'CUSTOM'
AND OBJECT_NAME LIKE 'BKP_%';

CHK_USER   VARCHAR2(32);
BEGIN
-- Grab the current user from Oracle.
SELECT USER
INTO CHK_USER
FROM DUAL;
-- If it is not CUSTOM, no nothing
IF CHK_USER = 'CUSTOM' THEN
  -- Loop through any tables that it found
  FOR PNT IN KILL_TABLES LOOP
    -- Get rid of the table.
     BEGIN
        EXECUTE IMMEDIATE 'DROP TABLE CUSTOM.'||pnt.OBJECT_NAME;
     EXCEPTION
        -- if the drop fails for any reason, keep going
        WHEN OTHERS THEN
           NULL;
     END;
  END LOOP;
END IF;
END BKP_cleanup;
/