Cardinal Relationships Between Segments

The following types of cardinal relationships between groups of data are supported:

• One-to-one (1:1).
• One-to-many (1:M).
• Many-to-many (M:M).

You can define these relationships between:

• Instances of different segments.
• Instances of the same segment. That is, a recursive or bill-of-materials relationship.
• Segments from the same type of data source.
• Segments from different types of data sources. For example, you can define the relationship between an Oracle table and a FOCUS data source. Note that you can join different types of data sources only by using the JOIN command, not by defining the join in the Master File or Access File.
• If you are using a network data source, you can also rotate the data source after you have defined it, creating an alternate view that reverses some of the data relationships and enables you to access the segments in a different order.