```json { "table_name": "report_charts", "primary_key": "jobs_id,chart_id", "candidates": [ { "rank": 0, "partition_key": "jobs_id", "partition_key_label": "primary_identifier", "partition_key_reasoning": "jobs_id is the primary entity organizing this dimension table. RPUV=3.96 indicates ~4 charts per job on average, which is a reasonable partition size. Uniqueness=0.253 and Top 3 Coverage=4.58% show good distribution across 116 distinct jobs. Semantically, charts belong to jobs (reports), making jobs_id the natural organizer.", "clustering_key": null, "clustering_key_label": null, "clustering_key_reasoning": "Dimension tables typically do not require clustering. chart_id provides secondary uniqueness but no temporal or natural ordering exists within a job's charts that would benefit from clustering.", "world_line": null, "session_column": null, "confidence": "HIGH", "notes": "This is a dimension table storing chart metadata for reporting jobs. The composite key (jobs_id, chart_id) uniquely identifies each chart. Partitioning by jobs_id groups all charts for a given report together, which aligns with typical access patterns (retrieve all charts for a report). The 7 chart types (01_table_sizes through 08_volume_distribution) are template-based visualizations generated per job." } ] } ```