Cardinality in the context of a query
Depending on the context, cardinality can be interpreted differently by the IBM® Cognos® Analytics with Watson query service.
The following examples show possible interpretations.
Example 1: Tables behaving as a dimension and a fact
In this example, Sales Branch behaves as a dimension relative to Order header, and Order header behaves as a fact relative to Sales branch.
Example 2: Four tables in a query
In this example, all four query tables are included in a query. Sales staff and Order details are treated as facts. Order header and Sales branch are treated as dimensions. In this scenario, Order header is present on the many side and the 1 side of the relationship. In this context, the Cognos Analytics query service treats Order header as a dimension table, and avoids double counting of any measures in this table.
Example 3: Three tables in a query
In this example, only three tables are included in a query from the previous example. Order details isn’t used. Order header is now treated as a fact. Sales staff continues to be treated as a fact.