Note that DuckDB can ingest SQLite tables. If you need OLAP on your SQLite system today instead of whenever this is stable, consider pairing up DuckDB. In the simplest case if you don’t need amazing latency and have small data (<1gb), I would copy the whole table from SQLite into an in-memory or temp file DuckDB, do your OLAP queries, then throw it away. For larger datasets, you can incrementally replicate the SQLite table into DuckDB by adding a logical clock column or something to the SQLite table, and then copy rows where logical_clock>last_duckdb_change before running your next DuckDB query.

We’re currently doing a bake-off between a few databases for small datasets (<10m rows) with dynamic schemas, and have pretty comparable read latencies between DuckDB and SQLite for our workflow, so you might be able to get away with switching wholesale from SQLite to DuckDB if you don’t do a lot of update.