My last question is if the DDL operator involved in the step "s_Load_Final" can achieve such a load process as fast as the update operator or is any other operator available to carry out this process (preserving RI/FK/populated and in a fast way)?
DDL operator is a SQL command send to the database, not a true "loading" operator.
It's fast because at this time in the process, all the data are in database, so teradata will naturally use parallelism to manipulate it.
If TPT Update fulfills your needs it's also ok :)
Ok Waldar, thank you very much for your explanation, it is all very clear and understandable.