How does LanceDB support multi-process concurrent access?

Because LanceDB is fundamentally an embedded library reading and writing files directly, multi-process concurrent access depends on the underlying storage backend's own concurrency guarantees, with the specifics differing between local filesystem use and object storage.

On local filesystem storage, safe concurrent multi-process writes are more limited, since coordinating writers across processes on a plain filesystem is inherently harder without a centralized arbiter; LanceDB is generally better suited to single-writer, multiple-reader patterns in this setup, or careful external coordination if multiple writers are genuinely needed.

On object storage backends like S3, and especially with LanceDB Cloud or Enterprise, concurrent access is handled through the versioned commit protocol: writes are committed atomically as new manifests, and LanceDB uses an optimistic concurrency approach where a writer checks that no conflicting commit happened since it started, retrying if a conflict is detected — which is what lets multiple processes safely read and, within limits, write to the same table without a traditional always-on database server coordinating every operation centrally.