N1QL and index - one more selective than another?

There was a post (Feb 2015) that indicated that with N1QL, there is no guarantee which index (if there were more than one) will get used (e.g., longest or most selective). I cannot find this information in the documents, so I am checking if this has been improved on with 4.x (current or beta)?

Thank you.
Regards, Steve

Hi @scheok,

If more than one index qualifies, N1QL will scan the qualifying indexes and intersect them.

You should use EXPLAIN to see the exact behavior for your specific queries.

Thanks,
Gerald