Thanks Wayne and everyone else for your insights.

I just wanted to be sure that i am not the only one who has faced this issue. 🙂

I'll do my analysis on...

All your guesses are true but my issues is not mainly about the performance but the weird behavior that is being demonstrated by SQL.

I am using 3 table variables and...

But i think we can do this easily using the expressions rather than going for an extra script task