Comment 1 for bug 1524135

It turns out we have an index on environment UUID and time (e,t) but we are doing a filter e and sort on (t, _id), but Mongo doesn't seem to do a good job noticing that it could use that index. So we have to explicitly match our index in order for sort to use it.
One option is to sort on (e, t) or maybe add an index so we could sort on (e, t, _id).

We're discussing whether we need to sort based on "_id".