Hi all.

Sometimes fixed uid for postgres can be useful. For instance, when postgres backups and archive wal on NFS volume. Of cause, NFS v.4 can be configured to to work with text usernames, but our sysadmins are not smart enough to do this. And without this there is a problem to work with NFS with dynamically assigned random uids.

According th the Debian Policy fixed uid must be in the range 60000-64999.

https://www.debian.org/doc/debian-policy/ch-opersys.html#uid-and-gid-classes

Аnd according to /usr/share/doc/base-passwd
64001 | mysql             | mysql-server

mysql already has reserved uid. PostgreSQL may have reserved uid in the same manner.