Jelena,
Thanks for your reply and your advice...
About the UUID...
Our BASIS person says "it is not advisable to change the standard UUID data type and length. If you could put the where used list of the UUID data element as you could see it is linked to many of the standard TABLE, this may affect the other standard processes".
But what I think is that we need to do this change. Does this change must be done manually, right? Does not affect other processes?
Again thanks,
Alfredo Rodríguez