Chapter 14 & 15Conceptual & Logical Database Design

Methodology

• Definition

• Conceptual database design

• Relational database - logical design

• Relational database - physical design

• Relational database - operation

• 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

• Physical database design– Implementing a database using specific data storage

structure(s) and access methods

Conceptual Database Design

• Entities • Relationships• Attributes (simple, no composite, no derived)• Attribute domains• Primary and candidate key attributes

– 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

– 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– Domain & enterprise– Inter & referential– Intra– Entity– legal

Relational Database - Logical Design

• Review– 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

Relational Database - Logical Design

• Mapping logical database to DBMS– Base relations– Integrity Rules– Referential integrity (delete & update)

• No action

• Cascade

• Set null

• Set default

• No check

Relational Database - Physical Design

• Implementing physical representation– Analysis transactions

– File organization• Indexes

• Disk space

• Security – Policy & procedure

– User view

– Access rules

– Tansmission

Relational Database - Operation

• Monitoring & tuning– User requirements– Organization requirements– Performance

Assignment

• Review chapters 5-6, 11-15, 24-26

• Read chapters 16-17

• Work on group project– Normalized database due date: