A referential join is a performance optimization technique used in SAP HANA Calculation Views. It is semantically similar to an inner join but operates under the assumption that referential integrity is maintained between the two tables (i.e., for every row in the fact table, a corresponding entry exists in the dimension table). The primary benefit is that the query optimizer can engage in "join pruning." If a query does not request any columns from the dimension table (the right table), the optimizer can completely avoid executing the join, thereby ignoring the unnecessary data source and improving query performance.

A. A referential join assumes referential integrity, which is related to cardinality, but it does not automate the setting of cardinality rules. The modeler must still define them.

B. Reusing join settings is not a specific function of the referential join type; it's a more general modeling environment feature, if available at all.

C. While referential joins are often used in a series (e.g., in a star schema), this is not the reason for choosing this specific join type over others like inner or left outer joins.

1. SAP HANA Cloud

SAP HANA Database Modeling Guide for SAP Business Application Studio

Section: "Creating Joins in the Join Node".

Reference Detail: The guide states

"The referential join is an optimized join... The query optimizer can decide to not execute the join if the fields from the right table are not requested by the query." This directly supports the concept of ignoring an unnecessary data source for performance.

2. SAP HANA Cloud

SAP HANA Database Performance Guide for Developers

Section: "Join Pruning".

Reference Detail: This guide explains join pruning as a key optimization feature. It details that when referential joins are used and the dimension table attributes are not needed

the join is eliminated from the execution plan

which is the technical basis for the correct answer.