Exam 10: Transaction Management and Concurrency Control

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.

Free

(True/False)

4.9/5

(39)

Question 1

Correct Answer:

Verified

True

As a rule,a(n)____________________ must unlock the object after its termination.

Free

(Short Answer)

4.7/5

(31)

Question 2

Correct Answer:

Verified

transaction

Explain the transaction log.What is its function?

Free

(Essay)

4.8/5

(30)

Question 3

Correct Answer:

Verified

A DBMS uses a transaction log to keep track of all transactions that update the database.The information stored in this log 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 DBMS keeps several copies of ____________________ to ensure that a disk physical failure will not impair the DBMS's ability to recover data.

(Short Answer)

4.9/5

(29)

Question 4

A growing phase in a two-phase lock is when a transaction acquires all the required locks without locking any data.

(True/False)

4.9/5

(34)

Question 5

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?

(Multiple Choice)

4.7/5

(40)

Question 6

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

(Multiple Choice)

4.9/5

(37)

Question 7

The phenomenon of uncommitted data occurs when two transactions are executed concurrently and the first transaction is rolled back after the second transaction has already accessed the uncommitted data-thus violating the isolation property of transactions.

(True/False)

4.9/5

(39)

Question 8

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

(Multiple Choice)

4.9/5

(32)

Question 9

Most multiuser ______________________________ automatically initiate and enforce locking procedures,where all locking information is managed by the lock manager.

(Short Answer)

4.8/5

(35)

Question 10

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.

(True/False)

4.9/5

(47)

Question 11

Atomicity indicates the permanence of the database's consistent state.

(True/False)

4.8/5

(35)

Question 12

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.

(Multiple Choice)

4.8/5

(45)

Question 13

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.

(Short Answer)

4.9/5

(36)

Question 14

What are the three basic techniques to control deadlocks?

(Essay)

4.7/5

(30)

Question 15

____________________ control is important because the simultaneous execution of transactions over a shared database can create several data integrity and consistency problems.

(Short Answer)

4.7/5

(41)

Question 16

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

(Short Answer)

4.8/5

(36)

Question 17

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

(Multiple Choice)

4.8/5

(41)

Question 18

Uniqueness ensures that no equal time stamp values can exist,and ____________________ ensures that time stamp values always increase.

(Short Answer)

4.9/5

(32)

Question 19

A(n)____ condition occurs when two or more transactions wait for each other to unlock data.

(Multiple Choice)

4.7/5

(34)

Question 20

Showing 1 - 20 of 70

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.

As a rule,a(n)____________________ must unlock the object after its termination.

Explain the transaction log.What is its function?

The DBMS keeps several copies of ____________________ to ensure that a disk physical failure will not impair the DBMS's ability to recover data.

A growing phase in a two-phase lock is when a transaction acquires all the required locks without locking any data.

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?

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

The phenomenon of uncommitted data occurs when two transactions are executed concurrently and the first transaction is rolled back after the second transaction has already accessed the uncommitted data-thus violating the isolation property of transactions.

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

Most multiuser ______________________________ automatically initiate and enforce locking procedures,where all locking information is managed by the lock manager.

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.

Atomicity indicates the permanence of the database's consistent state.

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.

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.

What are the three basic techniques to control deadlocks?

____________________ control is important because the simultaneous execution of transactions over a shared database can create several data integrity and consistency problems.

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

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

Uniqueness ensures that no equal time stamp values can exist,and ____________________ ensures that time stamp values always increase.

A(n)____ condition occurs when two or more transactions wait for each other to unlock data.

Database Systems

Data Models

The Relational Database Model

Entity Relationship (ER)Modeling

Advanced Data Modeling

Normalization of Database Tables

Introduction to Structured Query Language (SQL)

Advanced SQL

Database Design

Database Performance Tuning and Query Optimization

Distributed Database Management Systems

Business Intelligence and Data Warehouses

Database Connectivity and Web Technologies

Database Administration and Security

Filters