I have a document with a field of type: Hash which exhibits very poor performance when loading any records. Most of these documents have ~2500 keys in this hash field. It takes ~900ms to load a single document. If I query for a document without(:my_hash_field) the load time drops to ~30ms. Database is local so I don't think it is network latency.

This happens with both mongoid 3.1.6 and 4.0.0 under ruby 2.1.2. This seems to be very poor performance for simply loading a document. Is this kind of performance expected when loading a document with a 2500 key hash?