TY - GEN

T1 - Computing the Shapley Value of Facts in Query Answering

AU - Deutch, Daniel

AU - Frost, Nave

AU - Kimelfeld, Benny

AU - Monet, Mikaël

N1 - Publisher Copyright:
© 2022 ACM.

PY - 2022/6/10

Y1 - 2022/6/10

N2 - The Shapley value is a game-theoretic notion for wealth distribution that is nowadays extensively used to explain complex data-intensive computation, for instance, in network analysis or machine learning. Recent theoretical works show that query evaluation over relational databases fits well in this explanation paradigm. Yet, these works fall short of providing practical solutions to the computational challenge inherent to the Shapley computation. We present in this paper two practically effective solutions for computing Shapley values in query answering. We start by establishing a tight theoretical connection to the extensively studied problem of query evaluation over probabilistic databases, which allows us to obtain a polynomial-time algorithm for the class of queries for which probability computation is tractable. We then propose a first practical solution for computing Shapley values that adopts tools from probabilistic query evaluation. In particular, we capture the dependence of query answers on input database facts using Boolean expressions (data provenance), and then transform it, via Knowledge Compilation, into a particular circuit form for which we devise an algorithm for computing the Shapley values. Our second practical solution is a faster yet inexact approach that transforms the provenance to a Conjunctive Normal Form and uses a heuristic to compute the Shapley values. Our experiments on TPC-H and IMDB demonstrate the practical effectiveness of our solutions.

AB - The Shapley value is a game-theoretic notion for wealth distribution that is nowadays extensively used to explain complex data-intensive computation, for instance, in network analysis or machine learning. Recent theoretical works show that query evaluation over relational databases fits well in this explanation paradigm. Yet, these works fall short of providing practical solutions to the computational challenge inherent to the Shapley computation. We present in this paper two practically effective solutions for computing Shapley values in query answering. We start by establishing a tight theoretical connection to the extensively studied problem of query evaluation over probabilistic databases, which allows us to obtain a polynomial-time algorithm for the class of queries for which probability computation is tractable. We then propose a first practical solution for computing Shapley values that adopts tools from probabilistic query evaluation. In particular, we capture the dependence of query answers on input database facts using Boolean expressions (data provenance), and then transform it, via Knowledge Compilation, into a particular circuit form for which we devise an algorithm for computing the Shapley values. Our second practical solution is a faster yet inexact approach that transforms the provenance to a Conjunctive Normal Form and uses a heuristic to compute the Shapley values. Our experiments on TPC-H and IMDB demonstrate the practical effectiveness of our solutions.

KW - knowledge compilation

KW - provenance

KW - shapley value

UR - http://www.scopus.com/inward/record.url?scp=85132750366&partnerID=8YFLogxK

U2 - 10.1145/3514221.3517912

DO - 10.1145/3514221.3517912

M3 - פרסום בספר כנס

AN - SCOPUS:85132750366

T3 - Proceedings of the ACM SIGMOD International Conference on Management of Data

SP - 1570

EP - 1583

BT - SIGMOD 2022 - Proceedings of the 2022 International Conference on Management of Data

PB - Association for Computing Machinery

Y2 - 12 June 2022 through 17 June 2022

ER -