Downsampling a complete bucket

Hey together,

I’m relativly new to the InfluxDB-World. I’m so far really happy, I installed Influx DB 2.03 in a docker container. I create per week around 4 GB of data, far to much to keep in storage for longer periods.
So I started to try creating a downsampling task, but so far I just got to work that a specific measurement gets downsampled and put into another database for longterm-storage.
My goal is to create a task which downsamples a complete bucket (so every _field/_measurement in the bucket) every week into 1h-points, with that I could reduce my logterm datastorage requirements by a factor of 150.
Could anybody give me a tip or example how such a task/query could look like?

Thank you so mutch,
Paul from Heidelberg (Germany)