|-----------------------+-------+-------|
| query                 | flat? |    ms |
|-----------------------+-------+-------|
| single_groupby_mht    | yes   |  6622 |
| single_groupby_mht    | yes   |  6654 |
| single_groupby_mht    | yes   |  6679 |
|-----------------------+-------+-------|
| single_groupby_mht    | no    |  6625 |
| single_groupby_mht    | no    |  6640 |
| single_groupby_mht    | no    |  6653 |
|-----------------------+-------+-------|
| cpu_max_all_ht        | yes   | 12831 |
| cpu_max_all_ht        | yes   | 12863 |
| cpu_max_all_ht        | yes   | 12798 |
|-----------------------+-------+-------|
| cpu_max_all_ht        | no    | 12717 |
| cpu_max_all_ht        | no    | 12705 |
| cpu_max_all_ht        | no    | 12708 |
|-----------------------+-------+-------|
| double_groupby_m      | yes   | 42741 |
| double_groupby_m      | yes   | 43093 |
| double_groupby_m      | yes   | 42386 |
|-----------------------+-------+-------|
| double_groupby_m      | no    | 42610 |
| double_groupby_m      | no    | 42829 |
| double_groupby_m      | no    | 42824 |
|-----------------------+-------+-------|
| groupby_orderby_limit | yes   |  7123 |
| groupby_orderby_limit | yes   |  7121 |
| groupby_orderby_limit | yes   |  7111 |
|-----------------------+-------+-------|
| groupby_orderby_limit | no    |  7331 |
| groupby_orderby_limit | no    |  7348 |
| groupby_orderby_limit | no    |  7301 |
|-----------------------+-------+-------|
 
where
 
const single_groupby_mht = [
  {"$match":{"measurement":"cpu",}},
  {"$group":{
"_id":{"$dateTrunc":{"date":"$time","unit":"minute"}},
"max_usage_user":{"$max":"$usage_user"} // M = 1
  }},
  {"$sort":{"_id":1}}
];
 
const cpu_max_all_ht = [
  {"$match":{"measurement":"cpu",}},
  {"$group":{
    "_id":{"$dateTrunc":{"date":"$time","unit":"hour"}},
    "max_usage_idle":{"$max":"$usage_idle"},
    "max_usage_irq":{"$max":"$usage_irq"},
    "max_usage_softirq":{"$max":"$usage_softirq"},
    "max_usage_steal":{"$max":"$usage_steal"},
    "max_usage_guest":{"$max":"$usage_guest"},
    "max_usage_guest_nice":{"$max":"$usage_guest_nice"},
    "max_usage_nice":{"$max":"$usage_nice"},
    "max_usage_user":{"$max":"$usage_user"},
    "max_usage_system":{"$max":"$usage_system"},
    "max_usage_iowait":{"$max":"$usage_iowait"}
  }},
  {"$sort":{"_id":1}}
];
 
 
const double_groupby_m = [
  {"$match":{"measurement":"cpu"}},
  {"$group":{
"_id":{"time":{"$dateTrunc":{"date":"$time","unit":"hour"}},"hostname":"$tags.hostname"},
"avg_usage_softirq":{"$avg":"$usage_softirq"},
"avg_usage_steal":{"$avg":"$usage_steal"},
"avg_usage_guest":{"$avg":"$usage_guest"},
"avg_usage_user":{"$avg":"$usage_user"},
"avg_usage_system":{"$avg":"$usage_system"},
"avg_usage_iowait":{"$avg":"$usage_iowait"},
"avg_usage_irq":{"$avg":"$usage_irq"},
"avg_usage_nice":{"$avg":"$usage_nice"},
"avg_usage_idle":{"$avg":"$usage_idle"},
"avg_usage_guest_nice":{"$avg":"$usage_guest_nice"}
  }},
  {"$sort":{"_id.time":1,"_id.hostname":1}}
];
 
 
const groupby_orderby_limit = [
  {"$match":{
    "measurement":"cpu",
    "time":{"$gte": new Date("2016-01-01T00:00:00.000Z"),"$lt": new Date("2016-01-24T20:11:07.101Z")} 
  }},
  {"$group":{
    "_id":{"$dateTrunc":{"date":"$time","unit":"minute"}},
    "max_value":{"$max":"$usage_user"}
  }},
  {"$sort":{"_id":-1}},
  {"$limit":5}
];