1 Introduction
Next Generation Sequencing (NGS), a high-throughput, massively parallel technology for reading the DNA, has made gigantic steps in the last 10 years. The cost of producing a complete human sequence dropped to 1000 US in 2015 [30] and is expected to drop below 100 US in the next 2-3 years. Each sequence produces raw data in the form of short reads of genome strings, whose storage requires about 200 GByte; between 100 million and 2 billion human genomes will be sequenced by 2025 [39] , thereby generating the biggest big data problem for the mankind.