Peter Lee <peterlee3672(at)yahoo(dot)com> writes:
> Question: will Postgres databases (such as Postgres12 originally installed on a RHEL 6 server) continue to function properly after the server get O/S upgrade to RHEL 7??
Possibly, but why don't you do the OS upgrade first? RHEL6 has been
EOL for some time, so installing new functionality on a server that's
still running that doesn't seem like prudent sysadmin-ship.
The main hazard you'd be looking at if you do it in the other order
is that RHEL7 might have different locale sorting behavior, resulting
in effectively-corrupt indexes on text columns. For more info about
that see
https://wiki.postgresql.org/wiki/Locale_data_changes
That page claims that only the de_DE.UTF-8 locale changed in RHEL7,
but I don't know that I'd risk money on that being true.
regards, tom lane