Question

Explain How Dangling Tuples May Arise. Explain Problems That They May Cause?

Answer 1

Referential integrity ensures that a foreign key in one table will equal null or the value of a primary in the other table. For every tuple in a table having a referenced/foreign key, there should be a corresponding tuple in another table, i.e., for existence of all foreign keys in the original tables. If this condition is not satisfied, then it results in a dangling tuple. Cyclical checking is the control technique for the regular checking of accumulated data on a file against authorized source documentation. There is no cyclical integrity testing. Domain integrity testing ensures that a data item has a legitimate value in the correct range or set. Relational integrity is performed.