The RETURNING clause allows you to retrieve values of columns (and expressions based on columns) that were modified by an insert, delete or update. Without RETURNING you would have to run a SELECT statement after the DML statement is completed, in order to obtain the values of the changed columns. So RETURNING helps avoid another roundtrip to the database, another context switch in a PL/SQL block. Use this workout to get up to speed on the many ways you can use RETURNING.