wstrzalka <wstrzalka(at)gmail(dot)com> writes:
> archive_timeout is used for WAL shipping to standby server in my case
> (are there any other reasons?), but WAL is switched by the timeout
> even if there are no changes on the server.
This is intentional. Some people consider the arrival of a new WAL file
to be a good heartbeat monitor, and they want to see one go by every
so many seconds whether the database is busy or not.
regards, tom lane