Получение типа колонки в запросе

with t1 as (
select
100::int2 as col1,
200::int4 as col2,
'c'::char as col3,
'text1'::varchar(100) as col4,
'text2'::text as col5
)
select
col1, pg_typeof(col1),
col2, pg_typeof(col2),
col3, pg_typeof(col3),
col4, pg_typeof(col4),
col5, pg_typeof(col5)
from t1