PostgreSQL manager should raise exceptions for all unsupported features

[Nirav Shah]

Presently, postgresql manager doesn't have many definitions that could be called by the task manager.
We need to implement these definitions, and just raise an exception for all unsupported features.

As an example, it is possible for the task manager to call get_replication_snapshot. But since this definition doesn't exist in postgresql's manager.py, python will fail with an unhelpful message along the lines of "Exception during message handling" and "No such RPC function 'get_replication_snapshot'".

It would be much more helpful to the user, if we fail with raising a DatastoreOperationNotSupported exception.

[Denis M. (dmakogon)]

I agree with this, but how PostgreSQL driver can raise exception against replication snapshot if it doesn't support building master-slave replication in Trove? Take a look at replication strategy. And take a look at https://github.com/openstack/trove/blob/master/trove/instance/models.py#L706

[Amrith Kumar (amrith)]

Nirav, any updates on this?