204 search results - page 2 / 41 » Containment of Conjunctive Queries with Negation: Algorithms... |
DBPL
2001
Springer
13 years 9 months ago
2001
Springer
Abstract. We are interested in the theoretical foundations of the optimization of conjunctive regular path queries (CRPQs). The basic problem here is deciding query containment bot...
PODS
2006
ACM
14 years 5 months ago
2006
ACM
Query containment is a fundamental algorithmic problem in database query processing and optimization. Under set semantics, the query-containment problem for conjunctive queries ha...
AMW
2009
13 years 6 months ago
2009
Abstract. Rewriting of conjunctive queries using views has many applications in database and data integration. We investigate ways to improve performance of rewriting and propose a...
CIKM
2007
Springer
13 years 9 months ago
2007
Springer
How to improve search accuracy for difficult topics is an underaddressed, yet important research question. In this paper, we consider a scenario when the search results are so poo...
PODS
2010
ACM
13 years 10 months ago
2010
ACM
Both semantic and type-based query optimization rely on the idea that queries often exhibit non-trivial rewritings if the state space of the database is restricted. Despite their ...