Make a backup file or save a DB in PostgreSQL I have deployed for my data base in production a new groups of users;


An admin user with full access to the DB ;  
A read only user ;
A super admin user to manage all the DBs ;


The matter is for the backup file or the data base save file, can i just use the read only user to save the DB or i shall use the super admin user to insure all data will be saved.
First think about what you want to achieve with a backup. To my humble opinion, a dump is not a backup good enough for DR. It can help restoring to a point in time but with a dump you can not recover the transactions that were created since the 'backup' was taken.
So if you just want an SQL dump that allows you to restore to a time in the past and ignores all transactions made between the dump time and the restore time, you can do that with a user that has read only access to those tables.
If you want a real backup, one that also enables you to recover the transactions made since the backup, use pg_backup to make a physical backup of the database and regularly make wall backups (there is a parameter for that &quot;archive_command&quot;) and of course, your cluster needs archive_mode = ON, and wal_level to archive or replica (depends on version, replica for &gt;= 9.6) This backup needs to be done by the database owner, often the postgres OS user.