>I tried this code and it works correctly for me. The SET DATASESSION TO correctly activates the right data session. i.e. 1
>My question must be why are you trying to set the datasession anyway ?

As you may have seen in my reply, I found the problem.

As for the user of changing data session, there is various reasons for that. In my case, I have the defaut data session which contains some control files where I need to switch to it sometimes to get some values.