CREATE OR REPLACE FUNCTION delete_staging_data()
RETURNS void
LANGUAGE plpgsql
AS 
'
DECLARE
  tableName varchar(63);
  staging_cursor CURSOR FOR SELECT table_name FROM information_schema.tables 
   WHERE table_type = ''BASE TABLE'' AND table_schema NOT IN (''pg_catalog'', ''information_schema'') AND table_name LIKE ''_\_%''; 

BEGIN
OPEN staging_cursor;

LOOP
FETCH NEXT FROM staging_cursor INTO tableName;

EXIT WHEN NOT FOUND;

EXECUTE ''DELETE FROM TABLE '' || tableName;
COMMIT;

END LOOP;

CLOSE staging_cursor;
END; 
'

CREATE OR REPLACE FUNCTION delete_staging_data()
RETURNS void
LANGUAGE plpgsql
AS 
$$
DECLARE
  staging_cursor CURSOR FOR SELECT table_name FROM information_schema.tables 
   WHERE table_type = 'BASE TABLE' AND table_schema = ('public') AND table_name LIKE '_\_%'; 

BEGIN
FOR stmt IN staging_cursor LOOP

  EXECUTE 'TRUNCATE TABLE ' || quote_ident(stmt.table_name) || ';';

END LOOP;

END; 
$$