 Bigtable also underlies Google Cloud Datastore, which is available as a part of the Google Cloud Platform.Bigtable development began in 2004 and is now used by a number of Google applications, such as web indexing, MapReduce, which is often used for generating and modifying data stored in Bigtable, Google Maps, Google Book Search, "My Search History", Google Earth, Blogger.com, Google Code hosting, YouTube, and Gmail.Google's reasons for developing its own database include scalability and better control of performance characteristics.