The above methods can be used after the fact. Before the fact, you can add a column to the table called UPDATE_TIME defined with the DATE datatype. Then create a trigger on the table which sets the UPDATE_TIME column to SYSDATE on any INSERT or UPDATE command on the table. Determining the last updated row is as simple as querying for the row with the MAX(UPDATE_TIME) value. This method does require you to set up the column and trigger beforehand.
This was first published in July 2006