Originally, we only supported DuckDB in our cloud product Spice Firecache, but actually lost a customer because their use-case was optimized for an OLTP DB. Now, you can get a choice... down to the dataset level and still be able to join across them in a single query. With Spice, you can load both SQLite and DuckDB together in the same process for local materialization and acceleration.
Finally, Spice OSS does more than just data query. You can read about the vision to power AI-driven applications by co-locating data with models at https://docs.spiceai.org/intelligent-applications.