Run a read-only DuckDB SQL statement and return the rows as a markdown table.

Only a single SELECT (including WITH/DESCRIBE/SUMMARIZE/SHOW) or EXPLAIN statement is accepted; anything that writes data, files or settings is rejected. Read files by quoting their path in the FROM clause, e.g. SELECT region, sum(amount) FROM 'data/sales.parquet' GROUP BY 1.

Args: sql: The statement to run. max_rows: Row cap for this call (defaults to the server's limit).

Return the column names and types of a data file, plus its row count.

Works for any path DuckDB can read -- csv, parquet, json/ndjson, xlsx, compressed variants, globs matching many files, http(s) URLs and s3 URIs.

Args: path: File path, glob or URL, e.g. 'data/sales_*.parquet'. include_row_count: Set False to skip counting rows on very large inputs.

Show the first rows of a data file so you can see real values.

Args: path: File path, glob or URL. rows: How many rows to show (default 20).

List data files in a directory (local, or an s3:// prefix).

Args: path: Directory or bucket prefix to list. pattern: Glob pattern for the file name, e.g. '*.parquet'. recursive: Descend into subdirectories. data_files_only: Keep only extensions DuckDB can read; set False to see everything.

Profile a file's columns: null counts, approximate distinct counts, min/max and the most frequent values of low-cardinality columns.

This scans the whole file, so prefer describe_file when you only need types.

Args: path: File path, glob or URL. columns: Restrict to these columns (default: all). top_k: Number of most-frequent values to show; 0 to skip that pass.