I need to check for duplicate rows across the dataset's tables. Let me start by examining the largest tables for exact duplicates, then look for near-duplicates in key tables. {"action": "tool_call", "reasoning": "Check for exact duplicate rows in the largest table (columns_catalog) by comparing total row count against distinct row combinations", "tool": "query_sql", "args": {"sql": "SELECT COUNT(*) as total_rows, COUNT(DISTINCT (dataset_id, table_name, column_name, created_at, updated_at, phys_type, semantic_role, rough_kind, null_count, distinct_count, min_value, max_value, avg_value, median_value, stddev_value, top_values_json, sample_values_json, aggregation_role, coordinate, measure_unit)) as distinct_rows, COUNT(*) - COUNT(DISTINCT (dataset_id, table_name, column_name, created_at, table_name, column_name, phys_type, semantic_role, rough_kind, null_count, distinct_count, min_value, max_value, avg_value, median_value, stddev_value, top_values_json, sample_values_json, aggregation_role, coordinate, measure_unit)) as duplicate_count FROM raw.columns_catalog", "purpose": "Detect exact duplicate rows in columns_catalog", "source": "raw"}}