Question 4
(a) With reference to database management system, state:
- one difference between fragmentation and replication.
- two advantages of replication.
(b)List two:
- type of fragmentation;
- examples of relational database management system.
Observation
The expected answer is:
(a) (i) Difference between Fragmentation and Replication in Database management system
|
Fragmentation |
Replication |
I |
Refers to the breaking down of a relation into fragments/small portions. |
Refers to duplication of data or database objects or database from one database to another. |
II |
There is no duplication of data, database objects or databases. |
There is duplication of data, database objects or databases. |
III |
The splitting up of parts of the overall database across different sites. |
The process of maintaining updates to data across different sites |
(ii) Two advantages of replication
- Improved availability of data
- Improved performance
- Faster query evaluation / retrieval
- All resources are equally replicated regardless of their popularity/Same across locations
- Replicas have utilization rate proportional to their query rates
- Improved scalability
- Improved fault tolerance
- Simplified backup
- Enhanced disaster recovery
- Localised access
(b) (i) Types of fragmentation
- Horizontal fragmentation
- Vertical fragmentation
- Hybrid fragmentation
(ii) Examples of Relational Database Management System
- Oracle
- My SQL
- MSQL
- Microsoft SQL server
- DB2/IBM DB2
- PostgreSQL,
- SQLite
- MariaDB
- Microsoft Access
- Oracle Database
- IBM Informix
- Apache Derby
- H2 Database Engine
- Amazon Relational Database Service (Amazon RDS)
- Sybase ASE
The question tested the candidates’ knowledge of relational database management system. It was reported that most of the candidates who attempted this question demonstrated poor knowledge of the area tested.