Non-relational databases (often termed as NoSQL) have recently emerged and have generated both interest and criticism. Interest because they address requirements that are very important in large-scale applications, criticism because of the comparison with well known relational achievements. One of the major problems often mentioned is the heterogeneity of the languages and of the interfaces the...

The integration of multiple database technologies, including both SQL and NoSQL, allows using the best tool for each aspect of a complex problem and is increasingly sought in practice. Unfortunately, this makes it difficult for database developers and administrators to obtain a clear view of the resulting composite data processing paths, as they combine operations chosen by different query opti...

In this paper, we provide a novel approach for effectively and efficiently support query processing tasks in novel NoSQL crowdsourcing systems. The idea of our method is to exploit the social knowledge available from reviews about products of any kind, freely provided by customers through specialized web sites. We thus define a NoSQL database system for large collections of product reviews, whe...

Modern architectures make possible development in new algorithms for large data sets and distributed computing. The newly proposed versions can benefit both from faster computing on the multi core architectures, and intelligent programming techniques that use efficient procedures available in the latest programming studios. Frequently used algorithms to sort arrays of data in NoSQL databases is...

Order-preserving encryption (OPE) allows encrypting without losing information about the order relation between the encrypted data items. Thus, the execution of compare, order and grouping operations can be done like on plaintext data. In particular it allows databases to do range queries over encrypted data, which is a useful feature especially for cloud databases that usually run in untrusted...