126 search results - page 14 / 26 » The Complexity of Acyclic Conjunctive Queries |
ADL
2000
Springer
13 years 12 months ago
2000
Springer
A mediator system is a kind of a meta-search engine that provides a seamlessly integrated search service for diverse search engines (collections). Since collections of a mediator ...
ADC
1995
Springer
13 years 11 months ago
1995
Springer
Even if high-level query languages are used, query formulation may cause problems. This is notably so in case of large and complex application domains. Typical examples of these k...
PODS
2010
ACM
14 years 19 days 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 ...
PVLDB
2008
13 years 7 months ago
2008
This paper studies, for the first time, the management of type information for an important class of semi-structured data: nested DAGs (Directed Acyclic Graphs) that describe exec...
TIME
2002
IEEE
14 years 13 days ago
2002
IEEE
We show the expressiveness provided by a Labelled point-based metric model for specifying and reasoning about complex disjunctive temporal constraints. The model allows us to mana...