Friends, I have seen all the postings on this item. All except EmmersonAD do not have the slightest of the idea of what they are talking about. Well, the short and sweet answer, which can be tested any time, is the datatype of NULL is the datatype of the COLUMN to which it belongs. Hint : Try nvl(MyDate,'01/01/01') and nvl(MyDate,to_date('01/01/01','dd/mm/yy')) in a select statement, where in the table the column MyDate is a Date datatype column.

How Oracle stores a null value - it just does not store any value for the NULL value in the row which is stored in an Oracle Block. Understanding the Block level concepts of PCTFREE and PCTUSED better, can help you guys here.

Good Luck.