mause / buenavista

A Postgres Proxy Server in Python

Buena Vista: A Programmable Postgres Proxy Server

Buena Vista is a Python library that provides a socketserver-based implementation of the Postgres wire protocol (PDF).

I started working on this project in order to address a common issue that people had when they were using another one of my Python projects, dbt-duckdb: when a long-running Python process is operating on a DuckDB database, you cannot connect to the DuckDB file using the CLI or with a database query tool like DBeaver to examine the state of the database, because each DuckDB file may only be open by a single process at a time. Using Buena Vista, we can start a thread in a long-running Python process like dbt-duckdb so that we can run queries against the data from DuckDB while the process is running, without having to wait until it has finished. I've implemented a prototype of this idea within the Buena Vista library at examples/duckdb_server.py, and you can run it like so:

git clone https://github.com/jwills/buenavista.git
cd buenavista
PYTHONPATH=. python3 examples/duckdb_server.py [duckdb.dbfile]

in order to start a Postgres server on localhost:5433 backed by the DuckDB database file that you passed in at the command line (or by an in-memory DuckDB database if you do not specify an argument.) You should be able to query the database via psql in another window by running psql -h localhost -p 5433 (no database/username/password arguments required) or by using the DBeaver Postgres client connection. (Note: there is still some work to do around transaction handling and making the full DuckDB table/view catalog accessible to DBeaver, but most queries should run successfully.)