Exercise 26

Federated database:

A federated database is a system in which several databases appear to function as a single entity. Each component database in the system is completely self-sustained and functional. When an application queries the federated database, the system figures out which of its component databases contains the data being requested and passes the request to it. Federated databases can be thought of as database virtualization in much the same way that storage virtualization makes several drives appear as one.
In my past i have worked with bank, in which we faced the problem of load at year end. Using the Federated database the load for the system to search all the rows for single entity, will be eliminated by splitting the transaction by year. Users will often only look at transactions in the past year and the system will only need to touch one or two component databases (Shavit, 2008)