Since the path enumeration is a complete enumeration, the ORDER BY does not really matter. If you leave it out you will get a "breadth first" enumeration (ie, the same as ORDER BY hops). If you have an ORDER BY then if there is a choice of which path to extend first, it will be the one with the smallest pathDistance (in the case of ORDER BY pathDistance). However, notwithstanding the search order the result will be a complete enumeration of all paths (and partial paths) meeting the requirements.