how about this solution?
Does it have any caveats?
WITH upsert AS (INSERT INTO GUCIO (ID, NAZWA)
SELECT A.ID, A.NAZWA
FROM ALA A
ON CONFLICT (ID) DO UPDATE SET
nazwa = excluded.nazwa
RETURNING xmax,xmin, *)
select xmax as xmax_value
into txmaxu
from upsert;
delete
from gucio
where xmax = (select xmax_value from txmaxu where xmax_value <> 0 limit 1);
--
Sent from: https://www.postgresql-archive.org/PostgreSQL-general-f1843780.html
