{"id":"map-side-join-conflict-prefix","text":"When left and right datasets share a non-key field name, `_merge_records` disambiguates with `left_` and `right_` prefixes; this convention applies in all join types including `None`-fill paths for left joins","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-conflict-prefix","truth_value":"IN","reason":"premise"}]}}