```json { "table_name": "metric_readings", "table_type_tags": [ {"tag": "dimension", "confidence": 0.75}, {"tag": "state", "confidence": 0.30} ], "primary_type": "dimension", "insufficient_evidence": false, "entity": { "columns": ["reading_id"], "unique_per_row": true }, "time_axis": { "columns": ["period_start"], "kind": "event_time" }, "reasoning": "reading_id has Uniqueness 1.000 (RPUV 1.00), making each row unique information about one metric reading. The composite (metric_id, period_start, segment) forms a natural grain with 2 × 24 × 28 = 1,344 possible combinations far exceeding 580 rows, confirming this is not a complete snapshot table. period_start is a time column, but it describes WHEN the reading applies (an attribute), not an axis ordering actions or changes of the reading entity itself. The row records computed metric values (numerator/denominator/value) for a specific metric-period-segment combination, with computed_at as a processing timestamp. This is dimension: each reading_id is a unique catalog entry of a metric calculation result." } ```