Use derivative() to calculate the rate of change between subsequent values or aggregate.rate() to calculate the average rate of change per window of time. If time between points varies, these functions normalize points to a common time interval making values easily comparable.
Flux is going into maintenance mode and will not be supported in InfluxDB 3.0. This was a decision based on the broad demand for SQL and the continued growth and adoption of InfluxQL. We are continuing to support Flux for users in 1.x and 2.x so you can continue using it with no changes to your code. If you are interested in transitioning to InfluxDB 3.0 and want to future-proof your code, we suggest using InfluxQL.
For information about the future of Flux, see the following: