Writing them primarily, for example there isn't a super simple replacement for something like `derivative` (https://docs.influxdata.com/flux/v0.x/stdlib/univers

Writing them primarily, for example there isn't a super simple replacement for something like `derivative` (https://docs.influxdata.com/flux/v0.x/stdlib/universe/derivative/ https://docs.influxdata.com/flux/v0.x/stdlib/universe/deriva...) in timescaledb.