I need to compute the distinct value counts for categorical columns across the dataset. The inspect_columns result shows many VARCHAR columns with semantic roles like "classifier", "identifier", and "descriptive", but the distinct_count and approx_distinct_count fields are empty (showing as 0 or blank). Let me write a comprehensive SQL query to get actual distinct counts for categorical columns across the key tables. ```json { "action": "tool_call", "reasoning": "The inspect_columns metadata shows empty distinct_count values. I need to compute actual DISTINCT counts for categorical (VARCHAR) columns across the main tables. I'll query the columns_catalog metadata to identify all VARCHAR columns, then write aggregations to count distinct values in the largest tables.", "tool": "query_sql", "args": { "sql": "SELECT table_name, column_name, COUNT(DISTINCT column_name) as distinct_values FROM raw.columns_catalog WHERE duckdb_type = 'VARCHAR' GROUP BY table_name, column_name ORDER BY table_name, column_name LIMIT 50", "purpose": "Get list of VARCHAR columns to then compute their distinct value counts" } } ```