If concurrent queries are made with ON CONFLICT DO UPDATE, will every update take place sequentially?

Question

I have a need to insert into a table and ensure that one column is being incremented each time.

My insert looks like:

INSERT INTO my_tbl (id) VALUES ($1)
 ON CONFLICT (id) DO UPDATE SET total = my_tbl + 1 RETURNING *;

(where total = an integer field that defaults to 0)

Assuming I don't have any rollbacks or anything going on, is it safe to assume that multiple executions of this statement with the same parameters at once would be locked and ordered safely such that each execution would return (given the RETURNING * bit) three different values in the total field?

My apologies for the phrasing of this question and its title as I'm not sure how to categorize what I'm trying to do.

Answer 1

Yes, you can safely assume that. Concurrent updates to a single row are serialized by FOR UPDATE or FOR NO KEY UPDATE row locks.