InfluxDB is not only better integrated to Graphana but is also much better suited to capturing and processing time series data.
- Handles timestamped data natively
- Allows summary/aggregated data to be calculated & saved automatically - for example, I keep my detailed sensor data (at ~1 minute intervals) for 7 days but all the data is automatically aggregated to hourly data (avg, max & min) and kept indefinitely. InfluxDB does all of this itself.
- Native integration to Graphana.
The disadvantage is that you have to learn something that you will initially find a little more complex than standard SQL to begin with.
