WAEC Data Processing 2023 Theory — Question 8

Model answer

(a)(i) Difference between Fragmentation and Replication: Fragmentation: Refers to the breaking down of a relation into fragments/small portions. There is no duplication of data, database objects, or databases. The splitting up of parts of the overall database across different sites. Replication: Refers to duplication of data or database objects or database from one database to another. There is duplication of data, database objects, or databases. The process of maintaining up-to-date data across different sites. (ii) Two advantages of replication: Improved availability of data; 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 and disaster recovery; Localised access. (b)(i) Types of fragmentation: Horizontal fragmentation; Vertical fragmentation; Hybrid fragmentation. (ii) Examples of Relational Database Management System: Oracle; MySQL; 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.