发表机构
University of Oxford; King’s College London（牛津大学; 伦敦国王学院）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
Guanaco算法通过交织一致性、全局均匀性和关系连接三个原语，实现了近次模宽度时间的合取查询评估。
AI 中文摘要
我们提出Guanaco，一种用于执行合取查询评估的算法，其中，对于每个布尔合取查询和正数epsilon，该算法实现多项式时间，其指数等于次模宽度加上epsilon。该算法及其运行时间平滑地推广到一般合取查询。我们认为该算法及其分析非常简洁，事实上，它们共同构成了一个高度简单的论证，表明合取查询评估可以在本质上以次模宽度时间进行。在布尔合取查询的情况下，该算法基于交织三个简单原语：一个用于建立某种一致性形式的子程序；一个用于建立全局均匀性的子程序，简言之，根据需要划分关系以控制平均度与最大度之间的差异；以及一个将现有关系对连接以形成新关系的简单步骤。
英文摘要
We present Guanaco, an algorithm for performing conjunctive query evaluation where, for each Boolean conjunctive query, and positive epsilon, the algorithm achieves polynomial time with exponent equal to the submodular width plus epsilon. The algorithm and its running time generalize smoothly to general conjunctive queries. We believe the algorithm and its analysis to be notably simple, indeed, together we believe they form a highly simple argument that conjunctive query evaluation can be performed in essentially submodular width time. In the case of Boolean conjunctive queries, the algorithm is based on interleaving three simple primitives: a subroutine for establishing a form of consistency; a subroutine for establishing global uniformity, which, briefly speaking, partitions relations as needed to control discrepancies between average degree and maximum degree; and, a simple step that joins pairs of existing relations to form new relations.
