InfluxDB has introduced regular expressions in the SELECT clause, allowing users to specify multiple field keys without listing them all out. Additionally, InfluxQL does not currently support dropping specific field keys from a measurement, but users can work around this limitation by writing the desired field keys to a different measurement, dropping the original measurement, and then writing the saved field keys back to the original measurement. The selector function in InfluxQL returns a single point that includes the last value of one or more specified fields, with the timestamp being InfluxDB's null timestamp equivalent when multiple timestamps are involved.