Reflects the intersection of the synchronization state of a database that is joined to the availability group on the availability replica and the availability mode of the availability replica (synchronous-commit or asynchronous-commit mode):
0 = Not healthy. The synchronization_state of the database is 0 (NOT SYNCHRONIZING).
1 = Partially healthy. A database on a synchronous-commit availability replica is considered 
partially healthy if synchronization_state is 1 (SYNCHRONIZING).
2 = Healthy. A database on an synchronous-commit availability replica is considered healthy if synchronization_state is 2 (SYNCHRONIZED), and a database on an asynchronous-commit availability replica is considered healthy if synchronization_state is 1 (SYNCHRONIZING).