How to delete columns of a series in InfluxDB
There is no way to delete a "column" (i.e. a field or a tag) from an Influx measurement. Here's the feature request for that.
You'll have to SELECT INTO a different measurement, excluding the columns you don't want:
SELECT useful_field, nice_tag INTO new_measurement FROM measurement
Probably too late, but you can use
USE table_name, DROP SERIES FROM "my_column_name"