Columnar store PostgreSQL extension exists, here are two but I think I’m missing at least another one:

https://github.com/citusdata/cstore_fdw

https://github.com/hydradatabase/hydra

You can also connect other stores using the foreign data wrappers, like parquet files stored on an object store, duckdb, clickhouse… though the joins aren’t optimised as PostgreSQL would do full scan on the external table when joining.