The answer for this simple case is: "Yes". Rows are inserted in the provided order in the
VALUES expression. And if your
id column is a
serial type, values from the underlying sequence will be fetched in that order.
But this is an implementation detail and there are no guarantees. In particular, the order is not necessarily maintained in more complex queries with
WHERE conditions or joins.
You might also get gaps or other rows mixed in if you have concurrent transactions writing to the same table at the same time. Unlikely, but possible.
There is no "natural" order in a database table. While the physical order of rows (which is reflected in the system column
ctid) will correspond to their inserted order initially, that may change any time.
VACUUM and other commands can change the physical order of rows. To
SELECT rows in any particular order, you must add an
ORDER BY clause. Values for
id, once generated, are stable and decoupled from any physical order, of course.