systemd unit files for PostgreSQL on Debian/Ubuntu
--------------------------------------------------

Each cluster is run as a separate service, called postgresql@version/name.
As systemd prefers processes to not daemonize, pg_ctlcluster is invoked with
--foreground. Logging still goes to /var/log/postgresql. (If you prefer the
systemd journal, remove --stdlog from ExecStart postgresql@.service, or
configure the logging_collector.)

There is a parent service called postgresql.service, that starts/stops/restarts/
reloads all individual services that are configured as "auto" in
/etc/postgresql/*/*/start.conf.

The link between start.conf and postgresql.service is established by
postgresql-generator, which creates symlinks in
/var/run/systemd/generator/postgresql.service.wants/.

 -- Christoph Berg <myon@debian.org>  Fri, 18 Jul 2014 23:52:09 +0300