113 search results - page 11 / 23 » The containment problem for REAL conjunctive queries with in... |
EDBT
2006
ACM
14 years 8 months ago
2006
ACM
In this paper we present a novel approach for estimating the selectivity of XML twig queries. Such a technique is useful for approximate query answering as well as for determining...
PODS
2010
ACM
14 years 1 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 ...
SEMWEB
2009
Springer
14 years 3 months ago
2009
Springer
An important application of semantic web technology is recognizing human-defined concepts in text. Query transformation is a strategy often used in search engines to derive querie...
PODS
2004
ACM
14 years 8 months ago
2004
ACM
We study the problem of answering queries over sources with limited access patterns. Given a first-order query Q, the problem is to decide whether there is an equivalent query whi...
DBPL
1997
Springer
14 years 22 days ago
1997
Springer
We consider spatial databases that can be defined in terms of polynomial inequalities, and we are interested in monotonic transformations of spatial databases. We investigate a hi...