```json { "classifications": [ { "column": "id", "role": "identifier", "confidence": 1.0, "reason": "Primary key with unique values (438 distinct in 438 rows)" }, { "column": "tables_catalog_id", "role": "identifier", "confidence": 1.0, "reason": "Foreign key reference to tables catalog, unique per row" }, { "column": "dataset_id", "role": "identifier", "confidence": 1.0, "reason": "Dataset identifier with format d_XXXXXXXX, used for joining" }, { "column": "batch_id", "role": "identifier", "confidence": 1.0, "reason": "Batch identifier with format batch_XXXXXXXXXXXX, used for tracking processing batches" }, { "column": "method", "role": "dimension", "confidence": 1.0, "reason": "Categorical field indicating correlation method (only 'pearson' observed), used for filtering/grouping" }, { "column": "column_count", "role": "measure", "confidence": 0.95, "reason": "Numeric quantity representing count of columns, suitable for aggregation (avg/sum)" }, { "column": "columns_json", "role": "attribute", "confidence": 1.0, "reason": "JSON array of column names, descriptive content for display, not for grouping or aggregation" }, { "column": "matrix_json", "role": "attribute", "confidence": 1.0, "reason": "JSON correlation matrix data, descriptive content for display, not for grouping or aggregation" }, { "column": "computed_at", "role": "dimension", "confidence": 0.95, "reason": "Timestamp for filtering, grouping by time periods, or temporal analysis" } ] } ```