SQL: Using Top 1 in UNION query with Order By

Question

I have a table as below

Rate Effective_Date
---- --------------
5.6  02/02/2009
5.8  05/01/2009
5.4  06/01/2009
5.8  12/01/2009
6.0  03/15/2009

Answer 1

The Order By in a select statement that is part of a union is ignored. Hence your TOP 1 is selecting some arbitary record (likely the first record by the clustered key for the table).