(b) Shared Nothing architecture: Instead of using a common storage
pool such as SAN each server uses only own local storage,
allowing storage to be accessed at local disk speeds instead of
network speeds which also permits capacity to be increased by
adding more nodes. Costs are also reduced since the commodity
hardware can be used with ‘‘Shared Nothing’’ architecture.
(c) Elasticity: Elasticity of databases means dynamic expandedability.
When a new node is added to the mesh, some subset of data
is to be replicated in new nodes.
Elastic databases emphasizing BASE principles necessitate to
give-up traditional paradigm of ACID transactions. However, various
implementations can prioritize certain requirements of availability
over other requirements such as consistency. The following
NoSQLs also support elasticity in principle: