Fuzzy Group By Queries via RL-Instances in Conventional RDBMS

SQL group by queries allow grouping tuples in relational databases and computing aggregated values from the obtained sets of tuples, which makes them a particularly useful tool for data analysis. In this paper, we propose a way to solve this type of queries in a fuzzy environment, using fuzzy partitions of the domain of attributes according to Ruspini. The resolution of the query is carried out through the use of RL-instances and concepts from the theory of Representations by Levels, particularly a new method to derive RL-partitions from fuzzy partitions. The approach can be easily used in conventional systems through well-known SQL patterns.