In the Acme Auto example, why does the Maintenance entity contain the Vehicle ID?

The Maintenance entity contains the Vehicle ID primarily to establish a relationship between the Vehicles and Maintenance data types. This relationship allows the system to effectively link maintenance records to the specific vehicles they pertain to. By including the Vehicle ID in the Maintenance entity, it creates a foreign key reference that facilitates data integrity and makes it possible to perform joins when necessary.

With this structure, developers can easily create queries that fetch all maintenance activities associated with a particular vehicle, enhancing the ability to manage and analyze maintenance records in relation to the vehicles. This relational approach ensures that the data model remains organized and that the maintenance history is clearly associated with the correct vehicle, improving the overall efficiency of data operations.

While the other choices touch upon aspects of data organization and querying, they do not capture the primary purpose of including the Vehicle ID in the Maintenance entity as directly as establishing the join between the two data types.