Should I care about this error "failed to link /usr/bin/psql [...] exists and it is not a symlink"?

Ekaterina Amez <[email protected]> Tue, 3 Dec 2019 15:41:21 +0100
Newsgroups gmane.comp.db.postgresql.admin
Message-ID <[email protected]>
Hi all,

I'm installing postgres 9.6 in a CentOS 7 computer that already has 
postgres v9.2 installed (version that comes with CentOS installer) and 
I've seen the message of this mail's subject. It's the second machine 
where I see it, but previous one was a development server and I passed 
over it. But now I'm trying to make a guide to take this procedure to a 
Production server. I understand what this error is telling me, what I'm 
missing is if this has or can have any side effects.

The full installation log is (sorry for the parts in Spanish but I guess 
is more or less legible, if translation needed please ask):

*[root@test-replicas ~]#*  yum install postgresql96-server
[....]
Running transaction check
Running transaction test
Transaction test succeeded
Running transaction
   Instalando    : postgresql96-libs-9.6.16-2PGDG.rhel7.x86_64                                                                                                                                            1/3
   Instalando    : postgresql96-9.6.16-2PGDG.rhel7.x86_64                                                                                                                                                 2/3
failed to link /usr/bin/psql -> /etc/alternatives/pgsql-psql: /usr/bin/psql exists and it is not a symlink
failed to link /usr/bin/clusterdb -> /etc/alternatives/pgsql-clusterdb: /usr/bin/clusterdb exists and it is not a symlink
failed to link /usr/bin/createdb -> /etc/alternatives/pgsql-createdb: /usr/bin/createdb exists and it is not a symlink
failed to link /usr/bin/createlang -> /etc/alternatives/pgsql-createlang: /usr/bin/createlang exists and it is not a symlink
failed to link /usr/bin/createuser -> /etc/alternatives/pgsql-createuser: /usr/bin/createuser exists and it is not a symlink
failed to link /usr/bin/dropdb -> /etc/alternatives/pgsql-dropdb: /usr/bin/dropdb exists and it is not a symlink
failed to link /usr/bin/droplang -> /etc/alternatives/pgsql-droplang: /usr/bin/droplang exists and it is not a symlink
failed to link /usr/bin/dropuser -> /etc/alternatives/pgsql-dropuser: /usr/bin/dropuser exists and it is not a symlink
failed to link /usr/bin/pg_basebackup -> /etc/alternatives/pgsql-pg_basebackup: /usr/bin/pg_basebackup exists and it is not a symlink
failed to link /usr/bin/pg_dump -> /etc/alternatives/pgsql-pg_dump: /usr/bin/pg_dump exists and it is not a symlink
failed to link /usr/bin/pg_dumpall -> /etc/alternatives/pgsql-pg_dumpall: /usr/bin/pg_dumpall exists and it is not a symlink
failed to link /usr/bin/pg_restore -> /etc/alternatives/pgsql-pg_restore: /usr/bin/pg_restore exists and it is not a symlink
failed to link /usr/bin/reindexdb -> /etc/alternatives/pgsql-reindexdb: /usr/bin/reindexdb exists and it is not a symlink
failed to link /usr/bin/vacuumdb -> /etc/alternatives/pgsql-vacuumdb: /usr/bin/vacuumdb exists and it is not a symlink
   Instalando    : postgresql96-server-9.6.16-2PGDG.rhel7.x86_64                                                                                                                                          3/3
   Comprobando   : postgresql96-libs-9.6.16-2PGDG.rhel7.x86_64                                                                                                                                            1/3
   Comprobando   : postgresql96-server-9.6.16-2PGDG.rhel7.x86_64                                                                                                                                          2/3
   Comprobando   : postgresql96-9.6.16-2PGDG.rhel7.x86_64                                                                                                                                                 3/3

Instalado:
   postgresql96-server.x86_64 0:9.6.16-2PGDG.rhel7

Dependencia(s) instalada(s):
   postgresql96.x86_64 0:9.6.16-2PGDG.rhel7                                                           postgresql96-libs.x86_64 0:9.6.16-2PGDG.rhel7

¡Listo!
*[root@test-replicas ~]#*  ls -l /usr/bin/psql /etc/alternatives/pgsql-psql
lrwxrwxrwx. 1 root root     23 dic  3 12:37/etc/alternatives/pgsql-psql  ->/usr/pgsql-9.6/bin/psql
-rwxr-xr-x. 1 root root 449280 nov  6  2016/usr/bin/psql

I've searched this error, but the only thing I've found is something 
about alternatives system, and the command update-alternatives. But I 
don't fully understand this system (I'm used to Windows) and this means 
that when using the command I'm not sure about what I'm doing, and I 
can't go to a Production environment like this. An alternative to this 
could be copy all these files to another location and replace them with 
links to the copies. But this solution looks a bit ugly (don't know how 
to express better :D).

Should I go the easy way (copy files and replace original ones with 
links), is better the first option (update-alternatives) or is there 
another solution?

Thank you for your time,

Ekaterina