Geography/Mobility

Geography/Mobility

There may be organizational, network or security constraints on where data can be held and distributed. Objectivity/DB is a naturally distributed database and it uses distributed processing, so data storage, processing and query handling functionality can be located at the most appropriate facility.

Clients have a “Single Logical View” of the data, so given adequate bandwidth, data can be located anywhere. However, if the bandwidth between sites is low then it may be better to locate Query Agents close to the data to reduce network traffic. Likewise, partitioning the databases and locating their Lock Servers close to the clients that use them will also reduce network traffic. Database replication will also reduce the need to move the same data across the long distance network many times.

Mobile clients that are always connected are not a particular problem, given adequate bandwidth. However, clients that detach from the network and then reappear will require their own system services (schemas, catalogs and Lock Servers) and will almost certainly use Objectivity/HA database replication functionality. Figure 13 (below) shows a globally deployed federation with fixed and mobile sites.