When optimizing the performance of a sharded system, a lot of times you would want to make sure that most (ideally all) your queries are targeted, or how many shards are queried.

An example section might look like this:

{ query: {
  { byShards: {"1": XX, "2":XX, "2":XX, .... }},
  { configDB: {reload:XX, partial:XX}},
}}