code: function userOperatorLosesPrecision(selector, field) {
    var matcher = selector[field];
    var userOperator = getKey(matcher);
  
    return userOperator !== '$eq';
  }
docs: so when you do e.g. $eq/$eq, we can do it entirely in the database. but when you do e.g. $gt/$eq, the first part can be done in the database, but the second part has to be done in-memory, because $gt has forced us to lose precision. so that's what this determines