Row Level RLS function: Can the table be used in the function?

I need to write an RLS function to restrict access to a table based on the average of one of it's fields. Consider an employee table, EMP, in which there is a salary field.

	CREATE OR REPLACE FUNCTION rls_sal (
		p_schema_name IN VARCHAR2,
		p_object_name IN VARCHAR2
	)
		RETURN VARCHAR2
	IS
		l_return_val VARCHAR2(2000);
		l_avg_sal NUMBER;
	BEGIN
		select avg(sal) into l_avg_sal from emp;
		l_return_val := 'SAL > ' || l_avg_sal;
		RETURN l_return_val;
	END rls_sal;
	/

When I run "SELECT * FROM EMP" sqlplus "hangs", apparently forever. It seems like I have sent the system into an infinite loop. I seems plausible as the function could be firing the RLS policy recursively from within the function? What is the best approach/workaround?

I anxiously await your response..

Thanks!!
Craig Received on Wed May 16 2007 - 16:35:23 CDT