Insufficient Priviledges error when trying to execute the procedure from package - oracle

Question

Step 1 : I have created one package with procedures to create context and set value to the context.
create or replace PACKAGE Context_check AS
PROCEDURE set_context_vpd_proc (V_ISID in varchar2);
procedure set_context (v_isid_a in varchar2);
END Context_check;
create or replace PACKAGE BODY Context_check AS
PROCEDURE set_context_vpd_proc (V_ISID in varchar2)
AS
v_STAT VARCHAR2(200);
v_chk varchar2(2000);
BEGIN
DBMS_SESSION.SET_CONTEXT('VPD_CTX', 'ISID', V_ISID );
--v_STAT := '';
EXCEPTION
WHEN NO_DATA_FOUND THEN NULL;
END;
procedure set_context (v_isid_a in varchar2)
as
begin
EXECUTE IMMEDIATE 'CREATE OR REPLACE CONTEXT VPD_CTX using set_context_vpd_proc';
set_context_vpd_proc (v_isid_a);
EXCEPTION
WHEN NO_DATA_FOUND THEN NULL;
end set_context;
END Context_check;
Step 2: When I am trying to executing the procedure I am getting an error
EXECUTE Context_check.set_context('Ana');
Error starting at line 43 in command:
EXECUTE Context_check.set_context('Ana')
Error report:
ORA-01031: insufficient privileges
ORA-06512: at "SYS.DBMS_SESSION", line 114
ORA-06512: at "SEC_ADMIN.CONTEXT_CHECK", line 8
ORA-06512: at "SEC_ADMIN.CONTEXT_CHECK", line 20
ORA-06512: at line 1
01031. 00000 - "insufficient privileges"
*Cause: An attempt was made to change the current username or password
without the appropriate privilege. This error also occurs if
attempting to install a database without the necessary operating
system privileges.
When Trusted Oracle is configure in DBMS MAC, this error may occur
if the user was granted the necessary privilege at a higher label
than the current login.
*Action: Ask the database administrator to perform the operation or grant
the required privileges.
For Trusted Oracle users getting this error although granted the
the appropriate privilege at a higher label, ask the database
administrator to regrant the privilege at the appropriate label.
I have already given all the grants on that package.Still I am not able to execute this procedure.
Note : If I create the same procedures as stand alone ,its working fine and setting the context.

Answer 1

You need to create a context using a package, not using a procedure inside of a package.
Instead of
EXECUTE IMMEDIATE 'CREATE OR REPLACE CONTEXT VPD_CTX using set_context_vpd_proc';
Write
EXECUTE IMMEDIATE 'CREATE OR REPLACE CONTEXT VPD_CTX using Context_check';