Applications that save the “open state” to the network share should work fine with Duplicati. However, it obviously won’t work if the application stores the state on the local machine and Duplicati is running on the networkshare machine.
Just for the record on databases. The only way to reliably back up a database is by directly interacting with the database on the database layer.
The way to do this with Duplicati is to NOT backup the database, but instead run a database dump and back up those database dumps. Duplicati does not understand the database transactions so simply backing up the raw database is gambling on data consistency.
These dumps can either be scheduled outside Duplicati or run as part of the run-script-before option.