Exam 10: Transaction Management and Concurrency Control

Database transaction _____ restores a database from an inconsistent state to a previously consistent state.

If a(n) _____ is issued before the termination of a transaction, the DBMS will restore the database only for that particular transaction, rather than for all transactions, in order to maintain the durability of the previous transactions.

A lock guarantees the open use of a data item to multiple transactions.

A diskpage, or page, is the equivalent of a _____.

In the optimistic approach, during the_____ phase, a transaction scans the database, executes the needed computations, and makes the updates to a private copy of the database values.

An optimistic approach is based on the assumption that the majority of the database operations do not conflict.

In a heavily used database management system (DBMS), the prevention and detection of _____ constitutes an important DBMS function.

The DBMS guarantees that the semantic meaning of a transaction truly represents the real-world event.

A _____ lock allows concurrent transactions to access different rows of the same table.

What is transaction isolation and why it is important?

How does a shared/exclusive lock schema increase the lock manager's overhead?

Time stamping demands a lot of system resources because many transactions might have to be stopped, rescheduled, and restamped.

The information stored in the _____ is used by the DBMS for a recovery requirement triggered by a ROLLBACK statement, a program's abnormal termination, or a system failure such as a network discrepancy or a disk crash.

The _____ protocol ensures that transaction logs are always written before any database data is actually updated.