TOP 10 LARGEST DATABASES IN THE WORLD

1. World Data Center for Climate, Hamburg: 340 terabytes of archive data

2. National Energy Research Scirntific Computing Center, Oakland, USA: 2.8 petabytes of data operated by 2000 computational scientist

3. AT&T, San Antonio, USA: 323 terabytes of information, 1.9 trillion phone call records

4. Google, Mountain View, USA: 91 million search requests per day, accounts for 50% of all internet searches, virtual profiles of countless number of users

5. Sprint Nextel, Overland Park (USA): 2.85 trillion database rows, 365 million call details records processed per day, 70,000 call detail record insertions per second.

6. ChoicePoint, Alpharetta, USA: 250 terabytes of personal data, information on 250 people

7. YouTube, San Bruno, USA: 100 million videos watched per day, 65,000 videos added each day, 60% of all videos watched online, at least 45 terabytes of videos

8. Amazon, Seattle, USA: 59 million active customers, more than 42 terabytes of data

9. Central Intelligence Agency, Langley, USA: 100 Freedom of Information Act-items added each month, comprehensive statistics on 266 countries, unknown number of classified information

10. Library of Congress, Washington DC, USA: 130 million items (books, photographs, maps, etc.), 10,000 new items added each day, 5 million digital documents, 20 terabytes of text data

DATABASE DEFINITION
A comprehensive collection of related data organized for convenient access, generally in a computer. The most common database models in use are the relational, hierarchical and the network model.

DATA DEFINITION
Logically grouped units of information that are transferred between systems or stored in systems. In computer science and data processing, data are digital representations of information that can be read and processed by a machine. The information is first coded in signs, the structures of which are subject to strict rules. To gain useful information from data, they must be interpreted in a meaningful context. This process is called data mining.