Target Update Action - Need Clarification

[DS_SUPPORT]

I am trying to create a server job with two streams (Incremental and Destructive). I am having a Jobparameter which will tell whether it is Incremental Load or Destructive Load.

So From a Transformer I am having two links, I put the constraint for Link1 as Incremental and for the Second Link , I have put the Constarint as Destructive.

I am using the DRS stage as my Target Stage as we may need to connect to different Databases. For Link 1 , I have Set the Target Action as "Insert Else Update" and for the Second Link , I have put the Target Action as "Truncate and Insert". But the Problem is , Even when i Choose the Incremental in the Jobparameter, it is still Truncating the target Table, But no rows are going through the Second Link. I hope when Intializing the Job itself, the Truncate is happening. Is this the expected Behaviour or is there something wrong with my Code.

For overcoming this, I can write a simple server job , which will get the Tablename as parameter and Truncate it.

But I want to know, Is this is the expected behaviour or is there some thing wrong in my designing.

[chulett]

That is the expected behaviour. The truncation happens when the stage is 'opened' and the connection is established to the database, regardless of any rows actually going down the link.