How does Tuple-oriented relational calculus differ from domain-oriented relational calculus ?

Question

Assume there is one database in a system having multiple processes that are accessing this database.
If one process updates database table other processes should be notified. If someone has MySql C APIs document please send me.
Thanks in advance.

Answer 1

1. The tuple-oriented calculus uses a tuple variables i.e., variable whose only permitted values are tuples of that relation. E.g. QUEL
2. The domain-oriented calculus has domain variables i.e., variables that range over the underlying domains instead of over relation. E.g. ILL, DEDUCE.