Indexing elements of array

Hello I am wondering if this is possible in version 4.1

I have a document that looks like this.

Session document
aryEvents: [1,2,3,4]

And event documents that look like this which keys are referenced in the aryEvents in the Session document.
Event document
value: “I am He-man”

value: “I am Hulk”

value: “I am Iron Man”

value: “I am Spiderman”

I do a NEST to nest the values of the events inside the aryOfEvents in the session and I was wondering if I could add an index in the array to make this a faster NEST (join).

Adding an index would not help in this case. We are making NEST faster in 4.5.1. If you post your exact query, we can take a look.