Which of the following is a building working model of a database system?
A.
Prototyping
B.
Bottom-up approach
C.
Conceptual database design
D.
Top-down approach
Explanation:
Prototyping refers to the creation of a working model of the database system. The purpose of Prototyping is to
suggest improvements or even
add new features; to identify features of a system that work well, or are inadequate; to evaluate feasibility of a
particular system design; to
clarify a user’s requirements.
Answer D is incorrect. In a top-down approach, a schema is created through a series of successive
refinements, starting from the first
schema, which is gradually expanded by using appropriate modifications that increase the detail of thevarious
concepts. Moving from one
level to another, the schema is modified using somebasic transformations called top-down transformation
primitives.
Answer B is incorrect. In a bottom-up approach, thepreliminary specifications are broken down into smaller
components so that each
component describes a basic fragment of the specifications. These components are then represented by
schemas, some of which may consist
of single concepts. The schemas are later obtained to be integrated together until a final schema is obtained.
Answer C is incorrect. Conceptual database design is the process of constructing a model for the data at a
high level of abstraction
without using DBMS. It consists of the constructionof an Entity-Relationship schema, providing an optimal
description of the user
requirements.