[nojvek]

I wish postgres supports parquet file imports and exports. COPY command with csv is really slooooooooow. Even BINARY is quite slow and bandwidth heavy.

I wonder how open postgres is and what kind of pull requests postgres team considers? I'd like to learn how to contribute to PG in baby steps and eventually get to a place where I could contribute substantial features.

[ioltas]

There has been a patch to extend the COPY code with pluggable APIs, adding callbacks at start, end, and for each row processed: https://commitfest.postgresql.org/49/4681/.

I'd guess that this may fit your purpose to add a custom format without having to fork upstream.

[ssfak]

Using the pg_duckdb[1] is an option, if you can install extensions on your setup.

[1]. https://github.com/duckdb/pg_duckdb