JSON Input for IoTDB

[Julian Feinauer]

Hi folks,

I already created Issue https://issues.apache.org/jira/browse/IOTDB-742 in this 
direction but wanted to discuss a topic.
Since it is now possible to have measurements and devices below a measurement 
we could do a pretty one to one mapping between JSON (or other strucuted data) 
and IoTDB Representation.

E.g.

{
  „temp“ : 20.0,
  „speed“: 100,
  „design“ : {
    „color“: „blue“
  }
}

Could be inserted into a FIELD mycar and would then just be the series

- root.sg.dev.mycar.temp -> 20.0
- root.sg.dev.mycar.speed -> 100.0
- root.sg.dev.mycar.design.color -> „blue“

This works as long as there are no arrays.
For arrays I see two possibilities.
Either store them as „2 series“:

Root.sg.dev.mycar._idx
Root.sg.dev.mycar.arrayvalue

With [1, 2, 4] being represented as

Root.sg.dev.mycar._idx -> 0, 1, 2
Root.sg.dev.mycar.arrayvalue -> 1, 2, 4
(all with equal timestamp)

Or we have a special naming convention e.g. for an array

{
  „a“ : [1, 2, 4]
}

We would map it to three series

Root.sg.dev.mycar.a_0 <- 1
Root.sg.dev.mycar.a_1 <- 2
Root.sg.dev.mycar.a_2 <- 4

What do you think about that?

Julian