Field Level Validation: The typical scenario you have here is you present a screen with a list of values that you will need the user to enter.
In either case, both full and incremental backups can be performed.
It takes place as part of a cycle that begins with a full backup, which is then followed by a given number of incremental backups. Therefore, data validation should start with business process definition and set of business rules within this process.
But making sure that these are implemented in the development process rather than after the program is done will help minimize the burdon of integrating data validation in your application.
Server-side backups are generally faster, owing to the fact that client-side backups usually depend upon transport across networks.
Typically this is not a full time role once the database is configured and tuned and automated maintenance processes are in place.