```json { "table_name": "search_index_metrics", "primary_key": "id", "candidates": [ { "rank": 0, "partition_key": "dataset_id", "partition_key_label": "E", "partition_key_reasoning": "Primary entity perspective: each dataset has search indexes built over time. RPUV=4.67 (95 unique datasets across 444 rows) provides good partitioning granularity. Top 3 coverage 21.40% indicates reasonable distribution. Semantically groups all indexing events for a given dataset together.", "clustering_key": "created_at", "clustering_key_label": "S", "clustering_key_reasoning": "Temporal ordering axis for indexing events. 296 unique timestamps with monotonicity=0.667 (moderate temporal ordering). Orders indexing operations chronologically within each dataset's timeline.", "world_line": "dataset_id", "session_column": "batch_id", "confidence": "HIGH", "notes": "Primary perspective: dataset-centric view of search index build events. The batch_id (RPUV=3.02, 147 unique) serves as a natural session grouping for related indexing operations within a dataset." }, { "rank": 1, "partition_key": "batch_id", "partition_key_label": "E", "partition_key_reasoning": "Alternative entity perspective: batch-centric view. RPUV=3.02 (147 unique batches) provides viable partitioning. Top 3 coverage 6.08% shows good distribution. Groups all indexing operations that occurred within the same batch execution.", "clustering_key": "created_at", "clustering_key_label": "S", "clustering_key_reasoning": "Same temporal ordering as rank=0. Orders events chronologically within each batch's execution timeline.", "world_line": "batch_id", "session_column": null, "confidence": "MEDIUM", "notes": "Alternative perspective: batch-centric view useful for analyzing indexing operations grouped by batch execution. Less natural than dataset perspective but valid for batch-level analysis." } ] } ```