Você pode especificar as colunas de destino entre parênteses antes de
select cláusula:INSERT INTO T1
(c1, c_additional) -- here
SELECT
C1,
'needed_value' -- just select a constant here
FROM dblink(
'hostaddr=127.0.0.1 port=5432 dbname=DB2 user=postgres password=postgres',
'SELECT * FROM T2')
AS T2_row(C1 integer)
