Lecture 2

Question 1

Main Phases of Database Design

Answer 1

• Requirementsdocumentandanalysis:a specification of user requirements
• Conceptualdesign:ERModelisusedatthis stage, which is then translated to a relational schema
• Schemarefinement:(Normalization)Check relational schema for redundancies and related anomalies
• Physicaldatabasedesignandtuning: Consider typical workloads and further refine the database design

Question 2

ER Diagrams – The Basics

Answer 2

• Entity: an objects that exists and is distinguishable from other objects, e.g. Student, Course, Route, Climber
• Entity set: a set of entities of the same type that share the same properties or attributes
– Drawn as rectangles:
• Attribute: descriptive properties possessed by each member of an entity set, e.g., Name, Age, Height
– Drawn as ovals:
• Relationship: an association among several entities, e.g. a student enrolls in a course, a climber climbs a route, etc.
• Relationship set: a set of relationships with the same type
Courses
Name
– Drawn as diamonds:
Enrolls