postgres drop/truncate table plsql function

gistfile1.txt

\c metadata
CREATE OR REPLACE FUNCTION drop_tables(_schema text)
  RETURNS void AS
$func$
BEGIN
   EXECUTE (
      SELECT 'DROP TABLE '
             || string_agg(quote_ident(t.tablename), ', ')
             || ' CASCADE'
      FROM   pg_tables t
      WHERE  t.schemaname = _schema
   );
END
$func$ LANGUAGE plpgsql;

SELECT drop_tables('public');

DROP FUNCTION IF EXISTS public.drop_tables();