CHAR and NULL

CHAR fields always take up the space assigned to them. Now you may think that it wouldn't be the case if it was NULL because that is determined by a bitmask in the row data (this bit is always present in SQL Server 2000 even if your column is not nullable).

This was true in SQL Server 6.5 but not in SQL Server 2000. So if you really need a nullable CHAR field it may be better to define the field as VARCHAR.