Exam 10: Transaction Management and Concurrency Control

To determine the appropriate order of the operations,the scheduler bases its actions on concurrency control algorithms,such as ____________________ or time stamping methods.

The transaction recovery write-ahead-log protocol ensures that transaction logs are always written before any database data are actually updated.

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

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?

What is a rule that applies to the two-phase locking protocol?

A shared lock produces no conflict as long as all the concurrent transactions are read-write only.

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.

____ means that data used during the execution of a transaction cannot be used by a second transaction until the first one is completed.

The ____________________ interleaves the execution of database operations to ensure serializability.

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.

A ____ lock prevents the use of any tables in the database from one transaction while another transaction is being processed.

____ are required to prevent another transaction from reading inconsistent data.

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 diskpage.

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

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

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 semantically correct.

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.

____ requires that all operations of a transaction be completed.

Lock ____ indicates the level of lock use.