Question 1

To ensure consistency of the database,every transaction must begin with the database in an unstable state.

Accepted Answer

A) True 
 B)False

Question 2

A consistent database is ____.

Accepted Answer

A)  One in which all tables have foreign keys 
B)  One in which all data integrity constraints are satisfied 
C)  One in which all tables are normalized 
D)  One in which all SQL statements only update one table at a time

Question 3

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

Accepted Answer

A)  database-level 
B)  table-level 
C)  page-level 
D)  row-level

Question 4

A ____ lock locks the entire diskpage.

Accepted Answer

A)  transaction-level 
B)  table-level 
C)  page-level 
D)  row-level

Question 5

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

Accepted Answer

A) True 
 B)False

Question 6

Durability requires that all portions of the transaction must be treated as a single,logical unit of work in which all operations are applied and completed to produce a consistent database.

Accepted Answer

A) True 
 B)False

Question 7

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

Accepted Answer

A) True 
 B)False

Question 8

Most real-world database transactions are formed by only one database request.

Accepted Answer

A) True 
 B)False

Question 9

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

Accepted Answer

A) True 
 B)False

Question 10

The scheduler establishes the order in which the operations within concurrent transactions are executed.

Accepted Answer

A) True 
 B)False

Question 11

Explain the functions of shared and exclusive locks.

Accepted Answer

The answer of Explain the functions of shared and exclusive...

Question 12

During the ____ phase,a transaction scans the database,executes the needed computations,and makes the updates to a private copy of the database values.

Accepted Answer

A)  read 
B)  validation 
C)  write 
D)  shared

Question 13

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

Accepted Answer

The answer of Database transaction ____________________ restores a database from...

Question 14

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

Accepted Answer

A)  database-level 
B)  table-level 
C)  page-level 
D)  row-level

Question 15

If T1 has not unlocked data item Y,T2 cannot begin; if T2 has not unlocked data item X,T1 cannot continue.Consequently,T1 and T2 each wait for the other to unlock the required data item.Such a deadlock is also known as a(n)____________________.

Accepted Answer

The answer of If T1 has not unlocked data item...

Question 16

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

Accepted Answer

A)  serializability and durability 
B)  atomicity and isolation 
C)  serializability and isolation 
D)  atomicity and serializability

Question 17

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

Accepted Answer

The answer of The objective of ____________________ control is to...

Question 18

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

Accepted Answer

A) True 
 B)False

Question 19

When you read from or update a database,you create a transaction.

Accepted Answer

A) True 
 B)False

Question 20

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

Accepted Answer

The answer of The ____________________ interleaves the execution of database...

Exam 10: Transaction Management and Concurrency Control

To ensure consistency of the database,every transaction must begin with the database in an unstable state.

A consistent database is ____.

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

A ____ lock locks the entire diskpage.

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

Durability requires that all portions of the transaction must be treated as a single,logical unit of work in which all operations are applied and completed to produce a consistent database.

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

Most real-world database transactions are formed by only one database request.

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

The scheduler establishes the order in which the operations within concurrent transactions are executed.

Explain the functions of shared and exclusive locks.

During the ____ phase,a transaction scans the database,executes the needed computations,and makes the updates to a private copy of the database values.

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

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

If T1 has not unlocked data item Y,T2 cannot begin; if T2 has not unlocked data item X,T1 cannot continue.Consequently,T1 and T2 each wait for the other to unlock the required data item.Such a deadlock is also known as a(n)____________________.

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

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

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

When you read from or update a database,you create a transaction.

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