```json { "table_name": "titanic", "primary_key": "PassengerId", "candidates": [ { "rank": 0, "partition_key": "PassengerId", "partition_key_label": "primary_identifier", "partition_key_reasoning": "PassengerId is the unique identifier for each passenger. RPUV=1.00 (perfectly unique), Uniqueness=1.000, monotonicity=1.000 (strictly increasing). This is the natural primary key for a dimension table of Titanic passengers.", "clustering_key": null, "clustering_key_label": null, "clustering_key_reasoning": "Dimension tables typically do not require internal sorting. No temporal or sequential ordering is needed for passenger records.", "world_line": null, "session_column": null, "confidence": "HIGH", "notes": "This is a classic dimension table containing passenger attributes (demographics, ticket info, survival outcome). PassengerId uniquely identifies each row. The table contains 891 passengers with their characteristics at the time of boarding. No temporal axis exists—this is a snapshot of passenger manifest data. The _ingestion_timestamp and related metadata columns are ETL artifacts, not part of the business domain." } ] } ```