DuckDB analytical data boundary

Evidence-backed facts

1. DuckDB documents in-process analytical concurrency with optimistic concurrency control and separate read-write and read-only modes. informative
2. Multiple processes can read a native database in read-only mode; configuration and file ownership still determine whether access is allowed. informative
3. Concurrent writes within one process can succeed without row conflicts, while conflicting updates can fail and require explicit application retry policy. informative
4. A successful connection or query plan does not establish safe multi-process writes, transaction success, authorization, backup, or production suitability. informative

Primary sources