2021/08/04 by Zhang, Yihong, Wang, Yisu Remy, Willsey, Max +1 · 4 citations
#Databases (cs.DB) #FOS: Computer and information sciences #Programming Languages (cs.PL)
paper · doi:10.48550/arxiv.2108.02290
We present a new approach to e-matching based on relational join; in particular, we apply recent database query execution techniques to guarantee worst-case optimal run time. Compared to the conventional backtracking approach that always searches the e-graph "top down", our new relational e-matching approach can better exploit pattern structure by searching the e-graph according to an optimized query plan. We also establish the first data complexity result for e-matching, bounding run time as a function of the e-graph size and output size. We prototyped and evaluated our technique in the state-of-the-art egg e-graph framework. Compared to a conventional baseline, relational e-matching is simpler to implement and orders of magnitude faster in practice.