title: Binary Search in MongoDB array without index
body: <p>Ok, so I have a very big number of documents in a sharded collection, let's say 1million. Each document holds a SORTED array of documents of size 10000. </p>
  
  <p>In order to access the top-level documents fastly, MongoDB uses the shard order plus the index to quickly find the document in question. Nonetheless, once I reach the document, then I have to look which set of sub-documents(in the array) satisfy my query. Now, I know this array is sorted but MongoDB doesn't. Also, creating 1Million indices is too expensive. </p>
  
  <p>Therefore, my question is the following, is there a way to force MongoDB to binary search a sorted array without an index?</p>