ASP.NET 2.0 Interview Question:

can u explain one critical mapping?
performance issue which one is better? whether connected lookup tranformation or unconnected one?

Submitted by: Administrator

It depends on your data and the type of operation your doing.

If you need to calculate a value for all the rows or for the maximum rows coming out of the source then go for a connected lookup.Or,if it is not so then go for unconnectd lookup.Specially in conditional case like,we have to get value for a field 'customer' from order tabel or from customer_data table,on the basis of following rule:

If customer_name is null then ,customer=customer_data.ustomer_Id

otherwise

customer=order.customer_name.

So in this case we will go for unconnected lookup
Submitted by: Administrator