What is the expected output of an Aggregate with a "With or Without" join between two entities?

The expected output of an Aggregate with a "With or Without" join between two entities is indeed that it retrieves all records from the left entity, even if there is no match in the right entity. This characteristic aligns with the behavior of a LEFT JOIN in SQL, which captures all entries from the first specified entity (the left entity), while providing corresponding data from the second entity (the right entity) only when matches exist.

In scenarios where there are no matches found in the right entity for specific entries in the left entity, those entries from the left will still appear in the results but will display NULL or equivalent values for the fields from the right entity. This allows for the retention of all records from the primary dataset, which is especially useful in cases where you need to ensure that every record from the left entity is accounted for in your output, regardless of the completeness of relationships with the right entity.

In contrast, other types of joins such as INNER, FULL OUTER, and RIGHT JOIN do not produce such results, as they either filter out unmatched records or favor records from the right side. Understanding this concept is crucial for effectively utilizing data relationships in OutSystems and other data-driven applications.