Execute Parallel Snapshot

Column name to use as surrogate primary key for all tables during snapshot chunking. Useful for tables without primary keys or when a more efficient column exists for chunking.

Optional restrictive regex applied by the orchestrator to the physical tables the controller expands, across ALL triggered selectors. Matched (via search) against each physical's fully-qualified identifier <database-or-schema>.<table>, so it can narrow by DB/schema, table name, or a table-name suffix — the caller decides. Only matching physicals are snapshotted. Use to backfill a specific subset without re-snapshotting a regex source's full expansion. Null → no restriction.