Mongo DB Index creation limitations

Please consider below limitations before creating Index's in Mongo DB.

•  A collection cannot have more than 64 indexes.
•  Index entries cannot exceed 1024 bytes.
•  The name of an index must not exceed 125 characters (including its namespace).
•  In-memory sorting of data without an index is limited to 32MB. This operation is very CPU intensive, and in-memory sorts indicate an index should be created to optimize these queries.