342 search results - page 16 / 69 » Conjunctive Queries over Trees |
JCSS
2008
13 years 7 months ago
2008
We give a quadratic algorithm for the following structure identification problem: given a Boolean relation R and a finite set S of Boolean relations, can the relation R be express...
PODS
2010
ACM
14 years 25 days ago
2010
ACM
We investigate a higher-order query language that embeds operators of the positive relational algebra within the simply-typed λ-calculus. Our language allows one to succinctly de...
JAPLL
2010
13 years 6 months ago
2010
Answering queries over an incomplete database w.r.t. a set of constraints is an important computational task with applications in fields as diverse as information integration and ...
ICDE
2004
IEEE
14 years 9 months ago
2004
IEEE
We describe and evaluate a query minimization technique that applies to XQueries, which are nested, perform arbitrary joins, and freely mix bag and set semantics. These features c...
ICDE
2008
IEEE
14 years 9 months ago
2008
IEEE
Abstract-- Current twig join algorithms incur high memory costs on queries that involve child-axis nodes. In this paper we provide an analytical explanation for this phenomenon. In...