Which of the following properties of the database transaction has been defined in the given statement:”Either
all the changes or no changes have been made in thedatabase.”
A.
Durability
B.
Atomicity
C.
Consistency
D.
Isolation
Explanation:
Atomicity ensures that a transaction is either committed (i.e., all the changes made to the database are
permanently saved) or rolled back (i.e., no changeshave been made, and the database is recovered to its
original state).Answer D is incorrect. The isolation property ensures that a transaction is isolated from any
outside operation. This means that data in a transaction cannot be viewed in its intermediate state.
Answer A is incorrect. The durability property ensures that once the user has been notified about the success
of the transaction, the transaction will continue and will not revert. This implies that the transaction has been
checked for all data integrity constraints, and no constraint has been found violated.Answer C is incorrect. The
consistency property ensures that the database remains in a valid state before and after the transaction is
committed. This means that a transaction cannot violate business rules, or integrity constraints, of the
database. For example, if an integrity constraint states that an account cannot be debited if the balance is less
than $500, then any transaction violating this rulewill be aborted.