Transcript Conceptual and Logical Database Design

Chapters 15 &16
Conceptual and Logical Database
Design Methodology
Agenda
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Definition
Conceptual database design
Relational database - logical design
Example
Definition
• Design methodology
– Structured design approach using procedures,
techniques, tools and documentation aids
• Conceptual database design
– Constructing an information model, independent from
all physical consideration for an enterprise
• Logical database design
– Building an organization database based on a specific
data model
Conceptual Database Design
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Entities
Relationships
Attributes (simple, no composite, no derived)
Attribute domains
Primary and candidate key attributes
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Minimal set of attributes
Less change
Uniqueness in the future
Fewest characters
Easy to use by users
Relational Database - Logical Design
• Draw ER model
• Review
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Always binary with1 to many relationship
No complex relationship
No redundant relationship
No recursive relationship
No relationship with attribute(s)
Relational Database - Logical Design
• Normalize relations
– Primary key
– Foreign key
– BCNF
• Add constraints
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Domain & enterprise
Referential
Entity
legal
Relational Database - Logical Design
• Review
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Organization current & future needs
All user current & future requirements
Normalization (Boyce-Codd)
Relationship (one-to-one or one-to-many)
Redundancy
Constraints
• User approval
• Document
Points To Remember
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Definition
Conceptual database design
Relational database - logical design
Example
Assignment
• Review chapters 5-6, 11-16
• Read chapters 17-18
• Work on group project
– E-R and normalized database due date: