Is retrieve Many from association One have the same effect as retrieve the object from DB As I think both of them hit the database to get the data? (Example: Retrieve by association all the persons associated with a country) If so,What is the better in performance? And Why Mendix says in the documentation that association retrieve is the following: Retrieve the object(s) associated to an object by following an association. Changes to the association that have not been committed to the database can be retrieved only by using this type of retrieval.
Of course frequent database interactions are not good if you need robust app and brilliant performance. Hence think about a situation where there are multiple micro flows to be called one after another, think about a batch synchronization operation... hence in that scenario this kind of retrieval is useful as well as efficient.