```json { "table_name": "2015", "primary_key": "Country", "candidates": [ { "rank": 0, "partition_key": "Country", "partition_key_label": "primary_identifier", "partition_key_reasoning": "Country is the unique identifier for this dimension table with RPUV=1.00, uniqueness=1.000, and each country appears exactly once. This is a snapshot of happiness metrics for 158 countries in 2015.", "clustering_key": null, "clustering_key_label": null, "clustering_key_reasoning": "Dimension tables typically do not require clustering keys as they are reference data without internal ordering requirements.", "world_line": null, "session_column": null, "confidence": "HIGH", "notes": "This is a dimension table representing country-level happiness metrics for the year 2015. The table name itself indicates the temporal snapshot (2015), and cross_table_context shows similar tables for 2016-2019, suggesting this is part of a yearly dimension series. Country serves as the natural primary key with perfect uniqueness. The metadata columns (_ingestion_timestamp, _batch_id, etc.) are technical artifacts and not part of the logical schema." } ] } ```