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Data Integration and NoSQL Systems: A State of the Art

Data Integration is one of the older research problems in database area. It aims to combine data stored in different data sources and provide a unified view of data to the user.
 With the spread of a new generation of database systems, called NoSQL systems, data integration becomes more challenging, since we have to integrate data stored in systems that implement different data models and query languages. Inspired by these motivations, we provide in this paper an overview of data integration challenges and solutions in the context of NoSQL systems.