Preface In recent years, there is a growing interest in applying mathematical theories and meth- ods (algorithms, combinatorics, codes, etc.) to describe and analyse scientific regularities of massive, complex, and fast changing data produced via Next-Generation-Sequencing technology. Various algorithms and data structures were devised to efficiently solve bioin- formatics problems concerning comparing, searching, analysing, storing, compressing, and modelling this kind of data. These sequences are characterised in being massive and high-repetitive collections of nucleotides or amino acid sequences plus some metadata like quality score values. Following the success of the Royal Society meeting on the Storage and Indexing of Mas- sive Data, held last year in Chicheley Hall, UK, this second meeting intended to gather international researchers mainly from the fields of bioinformatics, computer science, and mathematical as well as R&D industry fellows in order to present scientific papers or sur- vey articles on the algorithmic advancements in Big Data technology. In this edition, sponsored by the the Algorithms and Bioinformatics Group at the Infor- matics Department of King’s College London, UK, and the Words and Automata Research Group at Mathematics and Informatics Department of University of Palermo, Italy, 9 orig- inal research papers have been accepted for presentation and an invited talk has been given by Prof Filippo Mignosi, dealing with new mathematical theories, methodologies, algo- rithms, and data structures for Big Data. We thanks all the participants and also we wish to thank all the members of the Pro- gram Committee for their collaboration in the reviewing process of the papers, and the colleagues of the Organizing Committee for their resourceful cooperation. April 2014 Costas S. Iliopoulos, Alessio Langiu 3