Multiple choice interview questions on distributed database

Multiple Choice Questions with Answers in Distributed Database

1. Which of the following would improve the availability of resources especially for reading in a distributed database system?

a) Fragmentation of database

b) Replication of database

c) Defragmentation of database

d) Tuning of database

View Answer

Answer: (b) Replication of database

Replication in distributed database system is a concept of having multiple copies of same data at different sites to increase the availability of resources.

2. ______________ is very much required to process a query in a distributed database.

a) Global System Catalog

b) Database Views

c) Triggers

d) None of the above

View Answer

Answer: (a) Global System Catalog

Data dictionary is an important component in DBMS. It is used for manipulating information regarding all database components in a DBMS. It stores information regarding tables, views, name of the tables, attributes, constraint details etc. Global System Catalog is just like Data Dictionary for Distributed Database System. It stores information like what and where about the data in a DDB.

3. Reliability and availability of a “Centralized Data Allocation” method is ___________ when compared to a “Completely Replicated Data Allocation“.

a) Highest

b) Average

c) Lowest

d) Not applicable

View Answer

Answer: (c) Lowest

Replication in distributed database system is a concept of having multiple copies of same data at different sites to increase the availability of resources.

In a centralized data allocation method only one copy of data available. Hence, availability is lowest. Due to only one copy of data, it is prone to single point of failure.

In a completely replicated data allocation method, due to availability of more than one copy of same data, the reliability and availability is high compare to centralized data allocation method.

4. If one site ABORTs while processing part of a distributed transaction t, all other sites processing part of t will also ABORT t. Which of the following ensures this?

a) Two phase locking protocol

b) Two phase commit protocol

c) Three phase commit protocol

d) All of the above

View Answer

Answer: (b) Two phase commit protocol

In two phase commit protocol, the transaction coordinator decides to ABORT the entire transaction if any of the participating sites cannot commit for some reasons.

5. Which of the following transparencies in distributed database design requires the end user or programmer to specify the database fragment names but need not specify where these fragments are located?

a) Transaction

b) Location

c) Local mapping

d) Fragmentation

View Answer

Answer: (b) Location

Location transparency refers to the fact that the command used to perform a task is independent of both the location of the data and the system on which an operation is carried out.

**********

Distributed database multiple choice questions with answers

TOPICS (Click to Navigate)

Pages

Tuesday, April 21, 2020