Data fragmentation, replication, and allocation in DBMS
By: Prof. Dr. Fazal Rehman | Last updated: September 23, 2024
What is data fragmentation in a distributed database system?
a) Dividing data into multiple copies
b) Breaking data into pieces and storing them at different locations
c) Encrypting data for security
d) Combining data from multiple sourcesAnswer: b) Breaking data into pieces and storing them at different locations
Which type of data fragmentation involves dividing a table into multiple parts, with each part containing a subset of the rows (records)?
a) Vertical Fragmentation
b) Horizontal Fragmentation
c) Mixed Fragmentation
d) ReplicationAnswer: b) Horizontal Fragmentation
What is vertical fragmentation in a distributed database system?
a) Storing different rows of a table at different locations
b) Dividing a table into columns and storing each column at different locations
c) Creating multiple copies of the entire table
d) Storing data in multiple formatsAnswer: b) Dividing a table into columns and storing each column at different locations
In data replication, what is the main objective?
a) To improve data consistency across nodes
b) To increase data availability and fault tolerance
c) To reduce data redundancy
d) To optimize data retrieval speedAnswer: b) To increase data availability and fault tolerance
What is the difference between full replication and partial replication?
a) Full replication involves replicating the entire database at every node, while partial replication involves replicating only a subset of data
b) Full replication is faster than partial replication
c) Partial replication involves storing multiple copies of data at one node
d) Full replication requires less storage space than partial replicationAnswer: a) Full replication involves replicating the entire database at every node, while partial replication involves replicating only a subset of data
Which type of data allocation strategy involves storing data at the location closest to where it is most frequently accessed?
a) Centralized Allocation
b) Local Allocation
c) Global Allocation
d) Partitioned AllocationAnswer: b) Local Allocation
In the context of distributed databases, what is ‘data allocation’?
a) The process of replicating data across multiple nodes
b) The strategy for storing data fragments in different locations based on access patterns
c) The encryption of data for secure transmission
d) The backup of data to prevent lossAnswer: b) The strategy for storing data fragments in different locations based on access patterns
Which of the following techniques is used to maintain consistency in a distributed database system where data is replicated across multiple nodes?
a) Two-Phase Commit Protocol
b) Vertical Fragmentation
c) Data Encryption
d) Data ShardingAnswer: a) Two-Phase Commit Protocol
In data fragmentation, what does ‘mixed fragmentation’ refer to?
a) Combining horizontal and vertical fragmentation techniques
b) Encrypting data before fragmentation
c) Fragmenting data into multiple copies
d) Using multiple databases to store the same dataAnswer: a) Combining horizontal and vertical fragmentation techniques
What is the primary benefit of data fragmentation in a distributed database system?
a) Increased data security
b) Improved data retrieval performance by reducing data access times
c) Simplified database design
d) Reduced need for backup and recoveryAnswer: b) Improved data retrieval performance by reducing data access times
Which of the following is a key challenge associated with data replication in distributed databases?
a) Data consistency and synchronization across multiple nodes
b) Decreased data redundancy
c) Centralized control of data
d) Reduced data access speedAnswer: a) Data consistency and synchronization across multiple nodes
What does ‘partial replication’ refer to in the context of distributed databases?
a) Replicating the entire database at multiple sites
b) Replicating only a subset of data or tables across multiple sites
c) Combining data from multiple databases into one
d) Storing data in a centralized locationAnswer: b) Replicating only a subset of data or tables across multiple sites
Which of the following describes the ‘centralized allocation’ of data in a distributed database system?
a) Storing all data at a single central location
b) Distributing data fragments across multiple locations
c) Replicating data across all nodes
d) Storing data based on access patternsAnswer: a) Storing all data at a single central location
What is the role of ‘metadata’ in managing data fragmentation and replication?
a) To define the structure and location of data fragments and replicas
b) To encrypt data for secure storage
c) To handle user authentication and authorization
d) To perform data backup and recoveryAnswer: a) To define the structure and location of data fragments and replicas
Which data allocation strategy involves distributing data based on the frequency of access to minimize network traffic?
a) Random Allocation
b) Proportional Allocation
c) Local Allocation
d) Centralized AllocationAnswer: c) Local Allocation
