Currently order of attributes in the command matters when computing its query shape. find({a: 1, b: 1}) and find({b:1, a: 1}) will have different shape even though they are semantically equivalent.

This limitation is causing difficulties for both operations team (specifying query settings per shape is now more complicated as it may require specifying settings on multiple instances of the same semantical shape) as well as for the analytics team that interprets $queryStats data.