True or False: To have measures come through joins, primary keys must be defined in all views involved in the join.

True or False: To have measures come through joins, primary keys must be defined in all views involved in the join.

• A. True
• B. False
• C. It depends on the database
• D. Only for complex joins

Answer: (A)

The statement is true. In Looker, when creating joins between views, primary keys must be defined to ensure that Looker can accurately match records between them. Primary keys uniquely identify each record in a view, which is essential for the correct aggregation and calculation of measures. Without defining primary keys in all views involved in the join, the framework cannot reliably determine how to combine the datasets. This could lead to ambiguous joins, resulting in inaccurate or incomplete results. Having primary keys in each view enables Looker to optimize queries and ensure data integrity, which is particularly important when measures are derived from multiple datasets. The requirement for primary keys is a fundamental part of maintaining data relationships in LookML, which allows for effective data modeling and analysis.

The statement is true. In Looker, when creating joins between views, primary keys must be defined to ensure that Looker can accurately match records between them. Primary keys uniquely identify each record in a view, which is essential for the correct aggregation and calculation of measures. Without defining primary keys in all views involved in the join, the framework cannot reliably determine how to combine the datasets. This could lead to ambiguous joins, resulting in inaccurate or incomplete results.

Having primary keys in each view enables Looker to optimize queries and ensure data integrity, which is particularly important when measures are derived from multiple datasets. The requirement for primary keys is a fundamental part of maintaining data relationships in LookML, which allows for effective data modeling and analysis.