Introduction to Logical Data Modeling

• Definitions
• Benefits of logical data modeling
• Data modeling vs. physical database design
• Roles involved in data modeling
• Steps in the data modeling process
• Example data model

Entities

• Identifying entities
• Validating entities
• Documenting "instances" of entities
• Distinguishing entities from attributes
• Naming entities
• Starting an Entity/Relationship (E/R) diagram
• Workshop

Relationships

• Identifying significant relationships
• Determining the "cardinality" or "degree" of a relationship
• One-to-One
• One-to-Many
• Many-to-Many
• Determining whether a relationship is optional or mandatory
• Giving a relationship a name
• Documenting the relationships in the E/R diagram
• Walking people through an E/R diagram
• Workshop
• Resolving Many-to-Many Relationships
• Real-world examples of many-to-many relationships
• Why many-to-many relationships are broken down into simpler relationships
• Identifying "association" or "intersection" entities
• Documenting the new relationships in the E/R diagram
• Workshop

Attributes and Normalization

• Defining and categorizing attributes
• Domains and integrity rules
• Unique identifiers/primary keys
• Foreign keys
• Occurrence population
• Normalization: validating the placement of each attribute
• Attribute does not repeat (first normal form)
• Attribute is dependent on its entire UID (second normal form)
• Attribute is dependent only on its UID (third normal form)
• Workshop

Subtypes and Supertypes

• Identifying subtypes: real-world examples of subtypes and supertypes
• Determining when entities are similar
• UIDs
• Attributes
• One-to-one relationships
• Creating subtypes and supertypes
• “Type” entities
• Using subtypes to apply fourth normal form
• Establishing the relationships of the sub- and super-entities to other entities
• Mutually exclusive vs. non-mutually exclusive subtypes
• “Role” entities to handle complex subtypes
• Workshop

Recursive Relationships

• Real-world examples of recursive relationships
• Discovering recursive relationships
• Determining whether the relationships are optional or mandatory
• Documenting the new relationships in the E/R diagram
• Hierarchical vs. Network recursive relationships
• “Structure” or ”Bill of Materials” entities: fifth normal form
• Workshop

Appendix: Implementing a Relational Database

• Relational database objects: tables, views, indexes, etc.
• Mapping logical objects to physical objects
• Denormalization
• Why
• How
• Pros/Cons
• Distributing databases
• Referential integrity