I need to compute the distinct value counts for all categorical columns across the dataset. The inspect_columns results show many VARCHAR columns marked as categorical, but the distinct_count and approx_distinct_count fields are empty (showing as 0 or blank). I need to write SQL to actually count distinct values. Let me start by getting a complete picture of which tables have categorical columns, then compute their distinct counts in batches. {"action": "tool_call", "reasoning": "First, I need to identify all categorical VARCHAR columns across all tables in the dataset. The metadata shows many such columns, but I need the complete list to compute distinct counts efficiently.", "tool": "query_sql", "args": {"sql": "SELECT table_name, column_name FROM meta.columns WHERE rough_kind = 'categorical' ORDER BY table_name, column_name", "purpose": "Get complete list of all categorical columns to compute distinct counts for", "source": "raw"}}