WIREFRAME: Two-phase, Cost-based Optimization for Conjunctive Regular Path Queries
نویسندگان
چکیده
منابع مشابه
Containment of Conjunctive Regular Path Queries with Inverse
Reasoning on queries is a basic problem both in knowledge representation and databases. A fundamental form of reasoning on queries is checking containment, i.e., verifying whether one query yields necessarily a subset of the result of another query. Query containment is crucial in several contexts, such as query optimization, knowledge base verification, information integration, database integr...
متن کاملNew Rewritings and Optimizations for Regular Path Queries
All the languages for querying semistructured data and the web use as an integral part regular expressions. Based on practical observations, finding the paths that satisfy those regular expressions is very expensive. In this paper, we introduce the “maximal partial rewritings” (MPR’s) for regular path queries using views. The MPR’s are always exact and more useful for the optimization of the re...
متن کاملRegular Path Queries in Lightweight Description Logics: Complexity and Algorithms
Conjunctive regular path queries are an expressive extension of the well-known class of conjunctive queries. Such queries have been extensively studied in the (graph) database community, since they support a controlled form of recursion and enable sophisticated path navigation. Somewhat surprisingly, there has been little work aimed at using such queries in the context of description logic (DL)...
متن کاملConjunctive Regular Path Queries in Lightweight Description Logics
Conjunctive regular path queries are an expressive extension of the well-known class of conjunctive queries and have been extensively studied in the database community. Somewhat surprisingly, there has been little work aimed at using such queries in the context of description logic (DL) knowledge bases, and all existing results target expressive DLs, even though lightweight DLs are considered b...
متن کاملOptimization Properties for Classes of Conjunctive Regular Path Queries
We are interested in the theoretical foundations of the optimization of conjunctive regular path queries (CRPQs). The basic problem here is deciding query containment both in the absence and presence of constraints. Containment without constraints for CRPQs is EXPSPACE-complete, as opposed to only NPcomplete for relational conjunctive queries. Our past experience with implementing similar algor...
متن کامل