<ipython-input-3-27ac99273376>:1: UserWarning: this is an initial implementation of Parquet/Feather file support and associated metadata. This is tracking version 0.1.0 of the metadata specification at https://github.com/geopandas/geo-arrow-spec
This metadata specification does not yet make stability promises. We do not yet recommend using this in a production setting unless you are able to rewrite your Parquet/Feather files.
To further ignore this warning, you can do:
import warnings; warnings.filterwarnings('ignore', message='.*initial implementation of Parquet.*')
db.to_parquet("db.pq", compression=None)