How to retrieve the Foreign key information in Oracle

I want to know how to retrieve the Foreign Key information in Oracle while using SQL Statement?

I have use three SQL statement to retrieve such information, but the performance is very bad.

The three SQL Statements are:
Select constraint_name, r_constraint_name from all_constraints where constraint_type = 'R' and table_name = table1;

Select column_name from all_cons_columns where constraint_name = cons1;

Select table_name, column_name from all_cons_columns where constraint_name = r_ccons1;

Do anyone know another method to retrieve the Foreign Key information which has better performance?

--
Posted via http://dbforums.com