Department of Computer Science
1501263 Intro. to Database Management Systems
Spring 2022-2023
iTBL 7
ID
Name
1- Discuss the main differences between the notation for EER schema diagrams and
UML class diagrams by comparing how common concepts are represented in each.
EER diagram:
Used for database design.
An entity is represented as a rectangle and attributes as ovals.
Operations are not exclusively specified.
Relationships are represented by diamonds.
Relationship attribute- oval with a line
UML class diagram:
Used for object-oriented analysis design.
Operations are specified exclusively.
Associations are represented by a line specifying association name on the line.
Link attribute – a box with a dashed line.
A class diagram is represented as a box with three sections specifying class name, attributes, and
operations.
2- Discuss the similarities and differences between an ontology and a database
schema.
Ontology:
Focus on meaning.
Ontology axioms.
To specify meaning.
May be used for integrity.
ISA hierarchy is a backbone.
Theorem proves: infer new information, ensure consistency.
Database schema:
Focus on data.
DB constraints: to ensure integrity, often hint at meaning.
Little emphasis on ISA hierarchy.
SQL engines: querying, views, data integrity
Data dictionary: generally separate from schema.