4.8. Conclusion
In this chapter, we defined four Big Data integration requirements in cloud environments: R1 (selection, discovery and deployment of data stores), R2 (uniform access to any data stores), R3 (integrated view on data stores) and R4 (global query processing and optimization). Even if data integration has been widely studied in the past, Big Data and Cloud Computing introduce new problems that question classical approaches. The use of an integrated global schema and an associated query language, for instance, is deeply questionable and some works are based on a minimum global schema. We have analyzed the literature regarding each requirement and presented a summary of this analysis. Our summary includes a comparison between studied works on the basis of the criteria that we addressed in our research objectives. We concluded this article by introducing a global summary concering the most relevant studied solutions and defining some open issues covering different requirements...