2026-08-20T15:07:42Z https://drops.dagstuhl.de/oai

oai:drops-oai.dagstuhl.de:22964 2025-03-21T09:58:46Z ddc:004 open_access

A Simple Algorithm for Worst Case Optimal Join and Sampling Capelli, Florent Irwin, Oliver Salvati, Sylvain join queries worst-case optimality uniform sampling We present an elementary branch and bound algorithm with a simple analysis of why it achieves worstcase optimality for join queries on classes of databases defined respectively by cardinality or acyclic degree constraints. We then show that if one is given a reasonable way for recursively estimating upper bounds on the number of answers of the join queries, our algorithm can be turned into algorithm for uniformly sampling answers with expected running time Õ(UP/OUT) where UP is the upper bound, OUT is the actual number of answers and Õ(⋅) ignores polylogarithmic factors. Our approach recovers recent results on worstcase optimal join algorithm and sampling in a modular, clean and elementary way. Schloss Dagstuhl – Leibniz-Zentrum für Informatik Florent Capelli and Oliver Irwin and Sylvain Salvati 2025 Is Part Of LIPIcs, Volume 328, 28th International Conference on Database Theory (ICDT 2025) InProceedings Text doc-type:ResearchArticle publishedVersion application/pdf doi:10.4230/LIPIcs.ICDT.2025.23 urn:nbn:de:0030-drops-229647 https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.ICDT.2025.23 eng https://creativecommons.org/licenses/by/4.0/legalcode