Good stuff, although I’m not quite sure about the fast OLAP use case.

If you’re already sharding by tenant for other reasons, OK… But I see CDC to a true OLAP system as more scalable.

PostgreSQL still needs real columnar tables in the core, hopefully one day

OLAP means different things to different people. For us, it's just making sure your admin dashboard keeps working basically:

  SELECT tenant_id, COUNT(clicks)
  FROM users
  GROUP BY tenant_id
  ORDER BY 2 DESC
  LIMIT 25;

Re OLAP: It's probably ~good enough~ for a lean team that's trying to keep the tech stack standard and/or doesn't have a dedicated data person to take advantage of a columnar store.