An experimental survey of regret minimization query and variants: bridging the best worlds between top-k query and skyline query

When faced with a database containing millions of tuples, a user may be only interested in a (typically much) smaller representative subset. Recently, a query called the regret minimization query was proposed toward this purpose to create such a subset for users. Specifically, this query finds a set of tuples that minimizes the user regret (measured by how far the user’s favorite tuple in the selected set is from his/her favorite tuple in the whole database). The regret minimization query was shown to be very useful in bridging the best worlds between two existing well-known queries, top-k queries and skyline queries: Like top-k queries, the total number of tuples returned in this new query is controllable, and like skyline queries, this new query does not require a user to specify any preference function. Thus, it has attracted a lot of attention from researchers in the database community. Various methods were proposed for regret minimization. However, despite the abundant research effort, there is no systematic comparison among the existing methods. This paper surveys this interesting and evolving research topic by broadly reviewing and comparing the state-of-the-art methods for regret minimization. Moreover, we study different variants of the regret minimization query that has garnered considerable attention in recent years and present some interesting problems that have not yet been addressed in the literature. We implemented 12 state-of-the-art methods published in top-tier venues such as SIGMOD and VLDB from 2010 to 2018 for obtaining regret minimization sets and give an experimental comparison under various parameter settings on both synthetic and real datasets. Our evaluation shows that the optimal choice of methods for regret minimization depends on the application demands. This paper provides an empirical guideline for making such a decision.