video reference here 

Hi, restoring the database on a new instance can be done either from the 'Manage Databases' (from the Odoo login page) or directly with the Postgres tools. The restore operation will require only the credentials of the destination Odoo instance (the admin_passwd value from the Odoo configuration file), if you use the Manage Databases method. For the latter one, you need run the restore commands as a database user (the db_user value from the Odoo configuration file). If you need further assistance, just let me know which method did you use for creating the backup. Anyway, you should try the restore with the unzipped file.

I hope this helps. Ioan