The architecture of distributed
database is basically composed of:
2) Fragmentation Schema: Each global relation can be split in to several non-overlapping portions which are called fragments. The mapping between global relations and fragments is defined in the fragmentation schema. This mapping is one to many, i.e., several fragments correspond to one global relation, but only one global relation corresponds to one fragment.
3) Allocation Schema: Fragments are logical portions of global
relations which are physically located at one or several sites of the network.
The allocation schema defines at which sites (s) a fragment is located.