server crash, need to restore DB functionality

Hello,

we run

7.4.7

on a Redhat RHEL server.

Today that was a severe server crash and NOC seems to have repeatedly
attempted a reboot without properly unmounting the file systems.

I am getting errors such as the following

Apr 29 13:15:34 cp postgres[4961]: [106-1] ERROR: could not open relation
"users_pkey": Permission denied
Apr 29 13:15:34 cp postgres[4961]: [107-1] ERROR: could not open relation
"users_pkey": Permission denied
Apr 29 13:15:34 cp postgres[4957]: [113-1] ERROR: could not open relation
"users_pkey": Permission denied

when attempting to have my application connect to the DB

Please let me know what sort of procedure are available to us
to have such functionality restored.

We do have backups.

Being it is one day old, are we going to loose information when attempting
to do a restore?

Any other procedures to save the data other than a restore?

Thanks.