DISTRIBUTED DATABASE SYSTEMS MCQ's

1.A distributed database has which of the following advantages over a centralized database?

a. Software complexity

b. Slow Response

c. Modular growth

d. Software cost

Correct Answer: c

2.A transaction manager is which of the following?

a. Maintains Sql Queries

b. Maintain Schema.

c. Maintains a log of transactions

d. Maintains database

Correct Answer: c

3.Some of the columns of a relation are at different sites is which of the following?

a. Data Replication

b. Horizontal Partitioning

c. Horizontal and Vertical Partitioning

d. Vertical Partitioning

Correct Answer: d

4.Storing a separate copy of the database at multiple locations is which of the following?

a. Horizontal and Vertical Partitioning

b. Data Replication

c. Horizontal Partitioning

d. Vertical Partitioning

Correct Answer: b

5.Which of the following is not one of the stages in the evolution of distributed DBMS?

a. Remote unit of work

b. Distributed unit of Work

c. Distributed reques

d. Unit of work

Correct Answer: d

6.Which of the following is a disadvantage of replication?

a. Each transaction may proceed without coordination across the network.

b. Each site must have the same storage capacity.

c. If the database fails at one site, a copy can be located at another site.

d. Reduced network traffic

Correct Answer: b

7.A distributed transaction can be …………. if queries are issued at one or more nodes.

a. fully read-write

b. partially read-write

c. partially read-only

d. fully read-only

Correct Answer: c

8.What is the mechanism which guarantees that all database servers participating in a distributed transaction either all commit or all roll back the statements in the transaction?

a. Commit transaction

b. Commit

c. Three-phase commit

d. Two-phase commit

Correct Answer: d

9.A characteristic of a file server is which of the following?

a. Acts as a fat client and is shared on a network.

b. Acts as a fat client and is limited to one PC.

c. Manages file operations and is shared on a network.

d. Manages file operations and is limited to one PC.

Correct Answer: c

10.Three-tier architecture includes which of the following?

a. A client layer and two server layers

b. Three server layers

c. Two client layers and one server layer

d. Three client layers

Correct Answer: a

11.Which of the following items are not necessary for client/server?

a. Assure that tools will connect with middleware.

b. Include the use of a file server.

c. Understand the requirements.

d. Determine network bandwidth capabilities.

Correct Answer: b

12.The three different application logic components are which of the following?

a. Presentation, Client, and Storage

b. Presentation, Processing, and Network

c. Presentation, Processing, and Storage

d. Presentation, Client, and Processing

Correct Answer: c

13.What is a data integrity?

a. It is the data contained in database that is secured

b. It is the data contained in database that is shared

c. It is the data contained in database that is accurate and consistent.

d. It is the data contained in database that is non redundant.

Correct Answer: c

14.In SQL the word ‘natural’ can be used with

a. right outer join

b. Semi join

c. inner join

d. full outer join

Correct Answer: c

15.Which of the following relational algebraic operations is not from set theory?

a. Union

b. Intersection

c. Cartesian Product

d. Select

Correct Answer: d

16.An entity set that does not have sufficient attributes to form a primary key is a

a. strong entity set

b. simple entity set

c. primary entity set

d. weak entity set

Correct Answer: d

17.In case of entity integrity, the primary key may be

a. both Null and not Null

b. any value

c. not Null

d. Null

Correct Answer: c

18.A logical schema

a. describes how data is actually stored on disk

b. describe meta data

c. is the entire database.

d. is a standard way of organizing information into accessible parts.

Correct Answer: c

19.Which of the following is another name for weak entity?

a. Child

b. Owner

c. Dominant

d. Parent

Correct Answer: a

20.Which of the following is record based logical model?

a. E-R model

b. None of the above

c. Network Model

d. Object oriented model

Correct Answer: c

21.A file manipulation command that extracts some of the records from a file is called

a. PROJECT

b. JOIN

c. PRODUCT

d. SELECT

Correct Answer: d

22.In E-R Diagram derived attribute are represented by

a. Triangle

b. Dashed ellipse

c. Ellipse

d. Rectangle

Correct Answer: b

23.The natural join is equal to

a. Combination of selection and Cartesian product

b. Combination of projection and Cartesian product

c. Cartesian Product

d. Combination of Union and Cartesian product

Correct Answer: b

24.All sites in a distributed database commit at exactly the same instant. TRUE/FALSE

a. TRUE

d. FALSE

Correct Answer: d

25.Which of the following parallel database architectures is/are mainly used by distributed database system?

a. Shared Disk

b. Shared Memory

c. Hierarchical

d. Shared Nothing

Correct Answer: d

26.Which of the following concurrency control protocol is suitable for an application where frequency of read operation is much greater than that of write operation?

a. Biased protocol

b. Quorum-consensus protocol

c. Majority protocol

d. Single lock protocol

Correct Answer: a

27.Centerlize and distributed databases are same

a. TRUE

d. FALSE

Correct Answer: d

28.Commit and rollback are related to ……….

a. data security

b. data consistency

c. data integrity

d. data sharing

Correct Answer: b

29.The transaction wants to edit the data item is called as …….

a. Unshared Mode

b. Exclusive Mode

c. Shared Mode

d. Inclusive Mode

Correct Answer: b

30.For committing a transaction, the DBMS might discard all the records.

a. before image

b. after image

c. log

d. redo log

Correct Answer: a

31.A sophisticated locking mechanism known as 2-phase locking which includes Growing phase and …

a. Release phase

b. Commit phase

c. Acquire Phase

d. Shrinking Phase

Correct Answer: d

32.A Transaction ends

a. only when it is Committed.

b. only when it is Rolled-back

c. only when it is initialized

d. when it is Committed or Rolled-back

Correct Answer: d

33.In ………., each transactions there is a first phase during which new lock are acquired.

a. Commit phase

b. Growing Phase

c. Shrinking Phase

d. Release phase

Correct Answer: b

34.A transaction processing system is also called as …….

a. processing monitor

b. transaction monitor

c. monitor

d. TP monitor

Correct Answer: d

35.The transactions are always ……… if it always locks a data item in shared mode before reading it.

a. well distributed

b. well locked

c. well shared

d. well formed

Correct Answer: d

36……….. servers which is widely used in relational database systems.

a. Data servers

b. Query servers

c. Client servers

d. Transaction servers

Correct Answer: d

37.If a distributed transactions are well-formed and 2-phasedlocked, then ……………. is the correct locking mechanism in distributed transaction as well as in centralized databases.

a. three phase locking

b. transaction locking

c. well-formed locking

d. two phase locking

Correct Answer: d

38………. property will check whether all the operation of a transaction completed or none.

a. Atomicity

b. Consistency

c. Isolation

d. Durability

Correct Answer: a

39.The total ordering of operations across groups ensures ………..of transactions.

a. synchronizability

b. atomicity

c. durability

d. serializability

Correct Answer: d

40.In which state, the transaction will wait for the final statement has been executed?

a. Failed

b. Aborted

c. partially committed

d. Active

Correct Answer: c

41.The ORDER concurrency control technique is based on the property.

a. ordering mechanism

b. inherent ordering

c. partial ordering

d. total ordering

Correct Answer: d

42.Transactions per rollback segment is derived from …..

a. Db_Block_Buffers

b. shared_Pool_size

c. buffers

d. Processes

Correct Answer: d

43.The …………is responsible for ensuring correct execution in the presence of failures.

a. Executive Manager

b. Database Manager

c. Transaction Manager

d. Recovery Manager

Correct Answer: b

44.A distributed transaction can be …………. if queries are issued at one or more nodes.

a. fully read-write

b. partially read-write

c. partially read-only

d. fully read-only

Correct Answer: c

45.The distributed transaction can be completely read-only and the transaction is started with a ………. READ ONLY statement.

a. READ TRANSACTION

b. DISTRIBUTED_TRANSACTIONS

c. SET TRANSACTION

d. TRANSACTION

Correct Answer: b

46.The initialization parameter …………….. controls the number of possible distributed transactions in which a given instance can concurrently participate, both as a client and a server.

a. CONTROL TRANSACTION

b. DISTRIBUTED_TRANSACTIONS

c. TRANSACTION

d. SET TRANSACTION

Correct Answer: b

47.A database administrator can manually force the COMMIT or ROLLBACK of a local ………… distributed transaction.

a. in-local

b. in-manual

c. in-doubt

d. in-force

Correct Answer: c

48.For using a specific database …………… command is used.