Using tags for providing floor to InfluxDB

Hi there!

On InfluxDB (0.9 and newer) - Persistence Services | openHAB I’ve come across the possibility to “group” items for storage in InfluxDB. I tried it and could get item names in InfluxDB, e.g.:

> show series from "room-temperature"

But I could not figure out how to get the items “tagged” by floor. From the documentation You can also add additional tags for structuring your data. For example, you can add a floor tag to all sensors to filter all sensors from the first floor or combine all temperature sensors into one measurement. I would have expected the following approach a or b to work.

I tried
a) tagging the individual items with “firstFloor”
b) tagging the individual items with “floor” (hoping for some magic behind the scenes)
c) I set the influxdb metadata as follows:

value: room-temperature
  floor: firstFloor

Ways a and b weren’t successful, but c worked. Is approach c really the one to use?

Can anybody give me a hint on that?

Best regards,