Increased efficiency is an advantage in a distributed database because data available locally can retrieved much more rapidly than data stored on a remote, centralized system. ... Additional requirements for storage space, Additional time for update operations, Complexity and cost of updating.
The number of bits in the network mask. BTW, that's called CIDR (Common Internet Domain Routing) format.
True!
A closed-loop system is essentially the same as an open-loop system, except a closed-loop system offers the element of feedback. Feedback allows the system to measure different variables and report it back to the controller.