Client APIs
The DuckDB Julia package provides a high-performance front-end for DuckDB. Much like SQLite, DuckDB runs in-process within the Julia client, and provides a DBInterface front-end.  
The package also supports multi-threaded execution. It uses Julia threads/tasks for this purpose. If you wish to run queries in parallel, you must launch Julia with multi-threading support (by e.g., setting the `JULIA_NUM_THREADS` environment variable).