Find all duplicate points in my database

If I have a measurement with multiple tags, I can insert multiple points with the same timestamp, if they differ in at least one tag. This is expected influx behavior.

I get data from various different IoT devices and store them all in influx measurements. I am wondering if I can write a query in which I can find all duplicates in all measurements efficiently, i.e. at best with a single query and no client side code detection.

Desired output: I have a measurement with 1.000.000 points, for one timestamp, I have two points due to different tags. I would like to have only those as result of my query.

Best regards