Chapter Summary

This chapter covered a lot on data modeling and database design concepts. You should have a firm grasp that the hub of data modeling circles is attributes and relationships. Nonetheless, other concepts were also covered.

KEY TERMS

• client/server

• Relational Database Management System (RDBMS)

• entities

• attributes

• relationships

• entity decomposition

• Primary Key

• one-to-one relationship

• one-to-many relationship

• many-to-many relationship

• Foreign Key

• normalization

• denormalization

Entities become tables in the physical design. Attributes become the columns of the tables. Relationships are used in the same manner in the physical database as they are in the logical model.

Normalizing the ER model helps remove redundant data. This normalization, however, can cause many small entities that need complex operations to print reports . Normalization can also be a detriment to server performance. In these instances, planned denormalization can provide for easier application development and better performance.

To complete the logical modeling, you define the data integrity rules. As you move toward the finalization of the logical model and into the physical design, you need to make other decisions based on data types and application development.

The process is never really finalized. As the database goes through its life cycle, changes will be needed to improve performance and/or meet the changing needs of the business. The next chapter elaborates on the integrity and design specifics for SQL Server. The physical implementation of the database will be a major exam focus.