InfluxDB WHERE clause on a 'High Cardinality' field (or a tag)

Question

I'm playing with InfluxDB and trying to experiment it for a vehicle speed tracking usecase. Every vehicle's speed at a given time is stored as a data point. I'm modelling "vehicle_registration" as a tag and other values as fields. I'd want the where clause to be applied on the "vehicle_registration" and it got to be quick. Therefore I'm taking advantage of the indexing capabilities on a tag by default. But the biggest stumbling block for me is that the tags need to have a lower cardinality. What are the recommendations here? I want a high cardinal field to be applied in a "where" clause and the queries should be quick.

Any advice?

Answer 1

High cardinality means higher memory requirement. So it really depends what high cardinality means in your use case. 1k will be probably fine for 8GB memory, but 1M will be probably problem for 8GB. The best option is to try it. Simulate it and you will see real memory requirements. Then you will be able to configure proper sizing for InfluxDB based on that (and your budget of course).

Or you can try TSI https://docs.influxdata.com/influxdb/v1.8/concepts/tsi-details/