my exam cloud quiz 2, join and cartesian product

[Himai Minh]

An inner join may be implicitly specified by the use of a cartesian product in the FROM clause and a join condition in the WHERE clause.
Given answer: True.

I think the answer should be false.
It returns a cartesian product. It should be a fetch join instead of an inner join.

[Frits Walraven]

This answer is true.

JPA specification:

4.4.5 Joins
An inner join may be implicitly specified by the use of a cartesian product in the FROM clause and a join condition in the WHERE clause. In the absence of a join condition, this reduces to the cartesian product. The main use case for this generalized style of join is when a join condition does not involve a foreign key relationship that is mapped to an entity relationship.

Example:
SELECT c FROM Customer c, Employee e WHERE c.hatsize = e.shoesize