Fuzzy Aggregators in Practice: Meta-Model and Implementation

The J-CO Framework is a tool designed to provide analysts and data engineers with the capability to perform complex transformations on JSON databases through its query language, named J- CO- QL+. Fuzzy aggregators are a powerful tool for decision making, when there is the need to combine together the evaluations of a group of experts to form a generalized opinion. Since soft querying can support decision making, it is straightforward to consider the introduction of the concept of fuzzy aggregation into J- CO- QL+. This paper proposes a generic meta-model to define fuzzy aggregators, and novel J- CO- QL+ constructs to define user-defined fuzzy aggregators and use them in practice. A plausible case study shows that the meta-model can be effectively implemented within a stand-alone query language (J- CO- QL+) that is supported by a tool (the J-CO Framework) that is available for the community.