SELECT FOR UPDATE locks all joined tables by default

FOR UPDATE locks selected rows to prevent concurrent modifications. If you don’t want to wait for locked rows, use NOWAIT to fail immediately or SKIP LOCKED to skip them, which is useful for queue-like tables.

By default, it locks rows from all queried tables, but you can limit it to specific ones using FOR UPDATE OF table_name. In a JOIN, only the rows that appear in the final result set are locked. If applied to a view, FOR UPDATE locks all underlying tables.

With LIMIT, locking stops once enough rows are fetched, but rows skipped by OFFSET still get locked.