anchor.diff:  
       environment.systemPackages = [postgresql];
   
  -    jobs.postgresql =
  +    boot.systemd.services.postgresql =
         { description = "PostgreSQL server";
   
           wantedBy = [ "multi-user.target" ];
  
positive.code: 
    postgresql = postgresqlAndPlugins cfg.package;
  
    run = "su -s ${pkgs.stdenv.shell} postgres";
  
    flags = optional cfg.enableTCPIP "-i";
  
    # The main PostgreSQL configuration file.
  
negative.code:             if ! test -e ${cfg.dataDir}; then
                  mkdir -m 0700 -p ${cfg.dataDir}
                  chown -R postgres ${cfg.dataDir}
                  su -s ${pkgs.stdenv.shell} postgres -c 'initdb -U root'
                  rm -f ${cfg.dataDir}/*.conf
              fi
  
              ln -sfn ${configFile} ${cfg.dataDir}/postgresql.conf
            ''; # */
  
          serviceConfig =
            { ExecStart = "@${postgresql}/bin/postgres postgres ${toString flags}";
              User = "postgres";
              Group = "postgres";
              PermissionsStartOnly = true;
  
              # Shut down Postgres using SIGINT ("Fast Shutdown mode").  See
              # http://www.postgresql.org/docs/current/static/server-shutdown.html
              KillSignal = "SIGINT";
  
              # Give Postgres a decent amount of time to clean up after
              # receiving systemd's SIGINT.
              TimeoutSec = 60;
            };
  
          # Wait for PostgreSQL to be ready to accept connections.
          postStart =
  