Export Data Marts to Parquet?

[coussens]

Thanks again for creating such a valuable open-source project!

I had a minor feature improvement suggestion, which is an option to export Data Marts as parquet files. This would benefit both users of SageRx as well as those downloading the exported Data Marts off of the CodeRx website:

• Columns would have data types, so there's no risk of users parsing from CSVs into different data types (e.g., the dreaded accidental conversion of NDCs to integers!)
• File sizes would be much smaller (leading to faster downloads, and less storage required)
• Better performance, integration with apache arrow, etc

This could be readily incorporated into the export_marts DAG in python, or even by incorporating the pg_parquet extension for Postgres.

Let me know what you think!