Exam 10: Transaction Management and Concurrency Control

requires that all operations of a transaction be completed.

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

ANSI defines four events that signal the end of a transaction. Of the following events, which is defined by ANSI as being equivalent to a ROLLBACK?

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

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

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

The reason for the different levels of isolation is to increase transaction concurrency.

A lock locks the entire diskpage.

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

A(n) phase in a two-phase lock is when a transaction releases all locks and cannot obtain any new lock.

A lock locks the entire table preventing access to any row by a transaction while another transaction is using the table.

Timestamps must only have the single property of uniqueness.

The objective of control is to ensure the serializability of transactions in a multiuser database environment.

ANSI defines four events that signal the end of a transaction. Of the following events, which is defined by ANSI as being equivalent to a COMMIT?

A single-user database system automatically ensures of the database, because only one transaction is executed at a time.

The rule states that only one transaction at a time can own an exclusive lock on the same object.

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.

Lock indicates the level of lock use.

The last step in the write-through technique recovery procedure is to identify the last checkpoint in the transaction log.

The approach to scheduling concurrent transactions assigns a global unique stamp to each transaction.