```json { "classifications": [ { "column": "id", "label": "primary_key", "confidence": 1.0, "reason": "100% distinct (2664/2664), zero nulls, VARCHAR with 'cnv_' prefix pattern indicating conversation ID" }, { "column": "tenant_id", "label": "foreign_key", "confidence": 0.95, "reason": "Single value 'default' across all rows, typical multi-tenant architecture foreign key" }, { "column": "dataset_id", "label": "foreign_key", "confidence": 0.98, "reason": "93 distinct values in 2664 rows (3.5%), 'd_' prefix pattern, references dataset table" }, { "column": "batch_id", "label": "foreign_key", "confidence": 0.98, "reason": "138 distinct values in 2664 rows (5.2%), 'batch_' prefix pattern, references batch table" }, { "column": "title", "label": "none", "confidence": 0.99, "reason": "Only 58 distinct values with 1.4% nulls, descriptive text field, not a key" }, { "column": "creator_fingerprint", "label": "foreign_key", "confidence": 0.9, "reason": "18 distinct UUID values in 2664 rows (0.7%), references user/creator table" }, { "column": "created_at", "label": "none", "confidence": 1.0, "reason": "Timestamp field, 100% distinct but temporal metadata, not a key" }, { "column": "updated_at", "label": "none", "confidence": 1.0, "reason": "Timestamp field, 100% distinct but temporal metadata, not a key" }, { "column": "message_count", "label": "none", "confidence": 1.0, "reason": "Metric field with only 6 distinct values (0-10), aggregate counter" }, { "column": "total_cost_usd", "label": "none", "confidence": 1.0, "reason": "Numeric metric field, cost aggregation, not a key" }, { "column": "total_tokens_in", "label": "none", "confidence": 1.0, "reason": "Numeric metric field, token count aggregation, not a key" }, { "column": "total_tokens_out", "label": "none", "confidence": 1.0, "reason": "Numeric metric field, token count aggregation, not a key" } ] } ```