Oracle is the world largest enterprise software company. Its business is based on information: helping people use it, share it, manage it, and protect it.
Using an Internet search engine, search using the terms Google and distributed database. Describe how and why Google uses a distributed database. What problems is Google encountering related to its distributed database? Google uses distributed databases in a few ways. One way is to store user settings and user ID information for the many Google services such as gmail, Google Alerts, personalized home page, and Google Answers. This distributed database of user settings is an Oracle database. Whenever a user logs in, and from wherever they log in, the distributed database can access and provide the appropriate user settings. An article at http://www.oracle.com/customers/snapshots/google-oracle-berkeley-db-casestudy.pdf indicates that:Read requests such as when an existing user returns and logs in are routed to any device in the partition, be it a master or a replica. However, updates to the database such as the addition of a new user or modification of an existing user data are routed only to the partition master. That master system records the change and then propagates it to the replicas. It considers the update complete when more than half the replicas have recorded the change. This design ensures that if a system failure occurs, the nodes can replicate the change among themselves and throughout the rest of the partition.