```json { "classifications": [ { "column": "favorite_id", "role": "identifier", "confidence": 1.0, "reason": "Primary key with unique values (212273 distinct out of 212273 rows), sequential integers 0-212272" }, { "column": "created_at", "role": "dimension", "confidence": 1.0, "reason": "Timestamp used for filtering, grouping by time periods, and temporal analysis" }, { "column": "user_id", "role": "identifier", "confidence": 1.0, "reason": "Foreign key referencing users table, used for joins and identifying which user created the favorite" }, { "column": "beer_id", "role": "identifier", "confidence": 1.0, "reason": "Foreign key referencing beers table, used for joins and identifying which beer was favorited" }, { "column": "list_id", "role": "dimension", "confidence": 0.95, "reason": "Low cardinality categorical code (4 distinct values: 0-3) representing different favorite lists, used for grouping and filtering" } ] } ```