Get usage of the schema

{"sql":"select usage from bangdb_stream"}

curl -H "Content-Type: application/json" -d' {"sql":"select usage from bangdb_stream"}' -X POST http://192.168.1.105:18080/stream/usage

{
   "rows":[
      {
         "k":9223372036854775807,
         "v":"{"fromts":0,"tots":9223372036854775807,"aggr_val":{"cnt":0,"sum":0,"min":0,"max":0,"avg":0,"stdd":0,"skew":0,"kurt":0}}"
      }
   ],
   "num_items":1,
   "more_data_to_come":0,
   "switch_done":0
}