Postgres is missing a proper columnstore implementation. It's a big gap and it's not easy to build.
One solution could be integrating duckdb in a similar way as pgvector. You need to map duckdb storage to Postgres storage and reuse duckdb query processor. I believe it's the fastest way to get Postgres to have competitive columnstores.
One solution could be integrating duckdb in a similar way as pgvector. You need to map duckdb storage to Postgres storage and reuse duckdb query processor. I believe it's the fastest way to get Postgres to have competitive columnstores.