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Preface
Information from multiple sources is growing at a staggering rate. The number of
Internet users reached 2.27 billion in 2012. Every day, Twitter generates more than
12 TB of tweets, Facebook generates more than 25 TB of log data, and the New
York Stock Exchange captures 1 TB of trade information. About 30 billion radio-
frequency identication (RFID) tags are created every day. Add to this mix the data
generated by the hundreds of millions of GPS devices sold every year, and the more
than 30 million networked sensors currently in use (and growing at a rate faster than
30% per year). These data volumes are expected to double every t ...