PostgreSQL - aplicar rtrim a todos los campos texto de una base de datos

DO $$

DECLARE

  sqltext text := 'The constructed select statement';

  rec1 record;

BEGIN

  FOR rec1 IN

        SELECT table_schema, table_name, column_name, data_type

        FROM information_schema.columns

        WHERE table_schema <> 'pg_catalog'

                AND table_schema <> 'information_schema'

                AND data_type IN ('character varying', 'text', 'character', 'char', 'varchar')

				and table_name = 'dbt10'

        LOOP

        sqltext := concat('update ', rec1."table_name" , ' set "',rec1."column_name" , '" = rtrim("' ,rec1."column_name" , '")');

    raise notice '%', sqltext;

	EXECUTE sqltext;

  END LOOP;

  END; $$