Create Materialized View Fails With ORA-30372

ORA-30372 error has been declared when user would like to refresh materialized view . Detailed explanation of error ,

Oracle Error: ORA-30372

Error Description:

Fine grain access policy conflicts with materialized view

Error Cause:

A fine grain access control procedure has applied a non-null policy to the query for the materialized view.

Action:

In order for the materialized view to work correctly, any fine grain access control procedure in effect for the query must return a null policy when the materialized view is being created or refreshed. This may be done by ensuring that the usernames for the creator, owner, and invoker of refresh procedures for the materialized view all receive a null policy by the user-written fine grain access control procedures.

If any table used in materialized view has VPD policy should return null while refreshing. This causes error and in order to solve this Oracle suggests to define policy function to user which will do operations to return NULL policy during create or refresh operations on materialized view.But it can cause security issues for this user who has some data access restrictions.

There is another solution .Following code can be put into security policy function and only while refreshing policy returns null.

if dbms_mview.i_am_a_refresh then

   return null;

end if;