The documentation puts a lot of emphasis on loading/querying existing files, as that's the first thing you will want to do for a OLAP use-case, but in general it's the same as sqlite where you maintain a database file.
Thanks. That's good to know. The file format is not highlighted in the documentation but I found some information about it: https://duckdb.org/internals/storage.html
It seems to be a bit early to rely on it to store data in an object store, but I will do some tests to compare with SQLite:
> The DuckDB internal storage format is currently in flux, and is expected to change with each release until we reach v1.0.0.
