Identifying Application Performance Requirements › Determining the Number of Entities in Each Relationship

Determining the Number of Entities in Each Relationship

To determine the sizing characteristics of the database, you will need to know the number of entities in each data relationship. For example, you will need to know the number of employees in each department to allow for effective placement of the EMPLOYEE and DEPARTMENT database entities.

Document both the expected and maximum number of entities in each relationship. If these numbers cannot be provided, use the statistics on numbers of entity occurrences gathered earlier to determine the numbers. For example, you can calculate the maximum number of employees in each department by dividing the maximum number of EMPLOYEE entity occurrences by the maximum number of DEPARTMENT entity occurrences.

Sample numbers of relationship entity occurrences

The following table shows the projected number of entity occurrences in three sample data relationships.