There is an example on UPDATE documentation page --
BEGIN; -- other operations SAVEPOINT sp1; INSERT INTO wines VALUES('Chateau Lafite 2003', '24'); -- Assume the above fails because of a unique key violation, -- so now we issue these commands: ROLLBACK TO sp1; UPDATE wines SET stock = stock + 24 WHERE winename = 'Chateau Lafite 2003'; -- continue with other operations, and eventually COMMIT;
Now we can use INSERT ... ON CONFLICT DO UPDATE command in this case.
My second reaction was why would we put either variant on the update command reference page.
Admittedly both of those examples are probably good to have somewhere, and I'm not sure where would be the most discoverable place.
I'd rather remove the example and write a paragraph pointing the reader to the savepoint and insert pages if they have a need to perform a conditional insert/update pairing.
