Biztalk Query notification clarification

Question

Hi,
I am getting weird behavior of Biztalk Query notification while updating the row.
i have a notification statement say for example,  like "select Custno from Customer where CUstNo = 2
when i insert row with cutno = 2 , biztalk gets notification . correct behavior
when i insert row with cutno = 1 , biztalk does not get notification . correct behavior
when i update row like update customer set custno = 2 where custono = 1  , biztalk gets notification . correct behavior
when i update row like update customer set custno = 3 where custono = 2  , biztalk also gets notification . i am not understand this ? why biztalk gets notified.
basically if we put where condition as custno = 2, 
biztalk gets notification for oth scenarios,   changing custno to "2" or Changing custno from "2"
can anyone clarify me how query notification works for Update statement?
Best Regards,
Vinoth

Answer 1

All of the scenarios you list appear to be the correct behavior since a row which satisfies your condition
may have been affected, in either the before or after set.
SQL Notifications lean toward over notification so you will get a notification when a row is touched though not necessarily modified.
Details here:
http://technet.microsoft.com/en-us/library/ms188323(v=sql.105).aspx