```json { "table_name": "data_dictionary", "table_type_tags": [ {"tag": "dimension", "confidence": 0.90} ], "primary_type": "dimension", "insufficient_evidence": false, "entity": { "columns": ["Table", "Field"], "unique_per_row": true }, "time_axis": null, "reasoning": "The composite entity (Table, Field) is unique per row — Table has 4 values, Field has 18 values with RPUV 1.17, and their product (4 × 18 = 72) far exceeds the 21 rows, confirming uniqueness. Each row describes one field in one table (metadata catalog). The four provenance columns (_ingestion_timestamp, _batch_id, _source_file, _source_system) are all constant synthetic values and carry no evidence. No time axis exists — this is a reference table defining the schema of sibling tables: dimension." } ```