2001/06/07 by F. Angiulli, Fabrizio Angiulli, Rachel Ben‐Eliyahu‐Zohary +9
Computer Science · #Computational Complexity (cs.CC) #Constraint Satisfaction and Optimization #Data Management and Algorithms #Databases (cs.DB) #F.2.0 #FOS: Computer and information sciences #H.2.3 #H.2.8 #Optimization and Search Problems #cs.CC #cs.DB
paper · pdf · doi:10.48550/arxiv.cs/0106012
32 pages. Partial and preliminary version appeared in Proc. of 19th Symposium on Principles of Database Systems, 2000, Dallas, pp. 237-244
arxiv created 2001/06/07 · openalex publication_date 2001/06/07 · arxiv updated 2009/11/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Metaquerying is a datamining technology by which hidden dependencies among several database relations can be discovered. This tool has already been successfully applied to several real-world applications. Recent papers provide only preliminary results about the complexity of metaquerying. In this paper we define several variants of metaquerying that encompass, as far as we know, all variants defined in the literature. We study both the combined complexity and the data complexity of these variants. We show that, under the combined complexity measure, metaquerying is generally intractable (unless P=NP), lying sometimes quite high in the complexity hierarchies (as high as NPPP), depending on the characteristics of the plausibility index. However, we are able to single out some tractable and interesting metaquerying cases (whose combined complexity is LOGCFL-complete). As for the data complexity of metaquerying, we prove that, in general, this is in TC0, but lies within AC0 in some simpler cases. Finally, we discuss implementation of metaqueries, by providing algorithms to answer them.