Column Level Security Using VPD under oracle 11g

Question

Hi
I am using an example from Oracle Database 10g: Advance Security -- Virtual Private Databases
1. The Application Context -- that sets the session environment for the use is ok.
2. The Logon Trigger that executes the above is ok. It had been tested.
3. The Security Policy that returns a predicate after checking the output of the Application Context is ok.
4. The security policy applied to the STOCK_TRX table is ok.
5. Select and Insert from the database work.
However, after dropping both the insert and select policy, I am having problem getting a select policy to work with column-level VPD. I will get the ORA-28104 -- input value for statement type is not valid and ORA-06512 at SYS.DBMS_RLS line 20. See code below
begin
DBMS_RLS.ADD_POLICY
('PRACTICE', 'STOCK_TRX', 'STOCK_TRX_SELECT_POLICY', 'PRACTICE', 'SECURITY_PACKAGE.STOCK_TRX_SELECT_SECURITY', 'PRICE');
end;
Note:
PRICE is the sec_relevant_cols
STOCK_TRX is the table
Can you please help.
Thx

Answer 1

The syntax for row level security is not the same for columns level security. All the parameters to the DBMS_RLS.ADD_Policy() function should be preceded by the type of the parameter for:
begin
DBMS_RLS.ADD_POLICy(object_schema=>PRACTICE, ... sec_relevant_cols=>'PRICE);
end;
I did not know this before. I thought they were there in the example for explanatory reasons. I decided to answer the question for myself because I know others have the same interpretation.