Exam 13: Managing Transactions and Concurrency

In the optimistic approach, during the ____ phase, changes are permanently applied to the database.

When using an optimistic approach, a transaction reads the database, executes the needed computations, and makes the updates to a private copy of the database values.

A transaction is a ____ unit of work that must be either entirely completed or aborted.

As long as two transactions, T1 and T2, access ____ data, there is no conflict, and the order of execution is irrelevant to the final outcome.

Incomplete or improper transactions can have a devastating effect on database integrity.

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.

When using an optimistic approach, during the write phase, the transaction is validated to ensure that the changes made will not affect the integrity and consistency of the database.

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.

Although the DBMS is designed to recover a database to a previous consistent state (when an interruption prevents the completion of a required set of transactions), the transactions themselves are defined by the end user or programmer and must be ____________________ correct.

____________________ can take place at any of the following levels: database, table, page, row, or field.