{"id":"map-side-join-no-real-parallelism","text":"Mapper parallelism is simulated via round-robin chunking and `_mapper_id` tagging on output records; no threads or processes are used","truth_value":"IN","source":"entries/2026/05/29/map-side-join-map_side_joins.md","source_url":"","source_hash":"","justifications":[],"dependents":[],"metadata":{},"explanation":{"steps":[{"node":"map-side-join-no-real-parallelism","truth_value":"IN","reason":"premise"}]}}