Oracle object dependancy

From dba_dependencies/user_dependencies/all_dependencies view you can know about dependencies between procedures, packages, functions, package bodies, and triggers.
You can know the dependent objects of a procedure ERROR_CODE by following query.
On which objects an object depends


SQL> col OBJECT_NAME for a30
SQL> SELECT object_name, object_type, owner, status, last_ddl_time FROM
dba_objects WHERE ( object_name, object_type ) IN ( SELECT
referenced_name, referenced_type FROM dba_dependencies WHERE name =
'ERROR_CODE' );

OBJECT_NAME OBJECT_TYPE OWNER STATUS LAST_DDL_
------------------------------ ------------------- ------------------------------ ------- ---------
DUAL SYNONYM PUBLIC VALID 14-OCT-07
STANDARD PACKAGE SYS VALID 14-OCT-07
SYS_STUB_FOR_PURITY_ANALYSIS PACKAGE SYS VALID 14-OCT-07
DBMS_OUTPUT SYNONYM PUBLIC VALID 14-OCT-07
REGISTERED_PHONES TABLE MAXIM VALID 15-FEB-09
SUBSCRIBERS TABLE MAXIM VALID 20-JAN-09
FIRST_LEG_SQ SEQUENCE MAXIM VALID 20-JAN-09
ACCESS_NUMBER TABLE MAXIM VALID 20-JAN-09
BLACKLIST_CALLER TABLE MAXIM VALID 20-JAN-09
DO_NOT_DIAL TABLE MAXIM VALID 20-JAN-09
HISTORY TABLE MAXIM VALID 20-JAN-09
RATE_PLAN_M TABLE MAXIM VALID 08-FEB-09
CHECK_ABILITY FUNCTION MAXIM VALID 20-JAN-09
SIGNUP FUNCTION MAXIM VALID 20-JAN-09
FIRST_LEG_ACC TABLE MAXIM VALID 25-JAN-09

15 rows selected.


Which Objects are Dependent on an object
Also, you can know the which objects are dependent on an object by using,


SQL> SELECT object_name, object_type, owner, status, last_ddl_time FROM
dba_objects WHERE ( object_name,object_type) in(SELECT name, type from
dba_dependencies
WHERE referenced_name='SUBSCRIBERS');

OBJECT_NAME OBJECT_TYPE OWNER STATUS LAST_DDL_
------------------------------ ------------------- ------------------------------ ------- ---------
AUTH_ERROR_CODE FUNCTION MAXIM VALID 25-JAN-09
CALRATE FUNCTION MAXIM VALID 01-FEB-09
CALRATEDUMMY FUNCTION MAXIM VALID 20-JAN-09
CALRATEDUMMY_800 FUNCTION MAXIM VALID 20-JAN-09
CALRATE_800 FUNCTION MAXIM VALID 20-JAN-09
CHECK_ABILITY FUNCTION MAXIM VALID 20-JAN-09
CHECK_ABILITY_800 FUNCTION MAXIM VALID 20-JAN-09
CREDIT_AMT_OR_TIME FUNCTION MAXIM VALID 20-JAN-09
GETCOUNTRYNAME FUNCTION MAXIM VALID 20-JAN-09
SIGNUP FUNCTION MAXIM VALID 20-JAN-09
SIGNUP_800 FUNCTION MAXIM VALID 08-FEB-09
MAP_TO_SPEEDDIAL PROCEDURE MAXIM VALID 20-JAN-09
UPDATE_USER_STATUS TRIGGER MAXIM VALID 19-FEB-09
UPDATE_HISTORY_FOR_REFUND TRIGGER MAXIM VALID 20-JAN-09
INSERT_HISTORY_DETAIL TRIGGER MAXIM VALID 20-JAN-09
DELETE_SUBSCRIBERS TRIGGER MAXIM VALID 20-JAN-09

16 rows selected.