Adam works as a Database Designer for DataOne Inc. The company has a SQL Server database. Adam
has to ensure that either all the databases are updated or none of them are updated, so that the
databases remain synchronized. Which of the following will he use to accomplish the task?
A.
Native auditing
B.
Two-phase commit
C.
Encryption
D.
Concurrency control
Explanation:
A two-phase commit is a feature of transaction processing systems, enabling databases to be
returned to the pre-transaction state if some
error condition occurs. A single transaction can update many different databases. A two-phase
commit strategy is designed to ensure that
either all the databases are updated or none of them, so that the databases remain synchronized.
Answer C is incorrect. Encryption provides an additional security layer, protecting the data from
unauthorized viewing with the help of
an algorithm called cipher. Even if access to the database is obtained, it will not be easy to decipher
encrypted data into a readable form.
Answer A is incorrect. Native auditing is the process of extracting trails on a regular basis so that
they can be transferred to a designated security system where the database administrators do not
have access. This ensures a certain level of segregation of duties and provides evidence that the
native audit trails were not modified by authenticated administrators.
Answer D is incorrect. Concurrency control in database management systems ensures that database
transactions are performed concurrently without the concurrency violating the data integrity of a
database. Executed transactions should follow the ACID rules. This mechanism is required to manage
multiple users accessing the same groups of resources with the least possible overhead, either
optimized for a specific task, or general purpose.
the two-phase commit protocol (2PC) is a type of atomic commitment protocol (ACP). It is a distributed algorithm that coordinates all the processes that participate in a distributed atomic transaction on whether to commit or abort (roll back) the transaction (it is a specialized type of consensus protocol).