一句话:重新证明有界扩张结构类上一阶查询可线性时间求值,并实现常延迟枚举与线性时间计数。
论文研究在有界扩张(bounded expansion)数据库类上评估一阶查询。有界扩张是一个较广的概念,推广了有界度、有界树宽和至少排除一个子图等结构类;此前已知一阶句子可在该结构类上线性时间求值。本文给出该结果的一个不同证明,并进一步证明一阶查询的答案可在线性时间预处理后以常数延迟枚举,且答案计数也可在线性时间内完成。
We consider the evaluation of first-order queries over classes of databases with bounded expansion. The notion of bounded expansion is fairly broad and generalizes bounded degree, bounded treewidth and exclusion of at least one minor. It was known that over a class of databases with bounded expansion, first-order sentences could be evaluated in time linear in the size of the database. We give a different proof of this result. Moreover, we show that answers to first-order queries can be enumerated with constant delay after a linear time preprocessing. We also show that counting the number of answers to a query can be done in time linear in the size of the database.
DOI 原文 · arXiv · PDF(开放获取) · DBLP
@article{abs-1802-04613,
title = {First-order queries on classes of structures with bounded expansion},
author = {Wojtek Kazana and Luc Segoufin},
journal = {Logical Methods in Computer Science},
volume = {Volume 16, Issue 1},
year = {2020},
doi = {10.23638/lmcs-16(1:25)2020}
}