Postgres tillader:
UPDATE dummy
SET customer=subquery.customer,
address=subquery.address,
partn=subquery.partn
FROM (SELECT address_id, customer, address, partn
FROM /* big hairy SQL */ ...) AS subquery
WHERE dummy.address_id=subquery.address_id;
Denne syntaks er ikke standard SQL, men den er meget mere praktisk til denne type forespørgsel end standard SQL. Jeg tror, at Oracle (i det mindste) accepterer noget lignende.