postgresql is missing!

$ sudo serveradmin list
accounts
addressbook
afp
alerts
bonjour
caching
calendar
certs
collabd
config
devicemgr
dhcp
dirserv
dns
filebrowser
firewall
ftp
history
info
jabber
mail
netboot
network
nfs
radius
san
sharing
signaler
smb
status
swupdate
timemachine
vpn
web
wiki
xcode

Onur9999 about macOS Server, v4.0