342 search results - page 32 / 69 » Conjunctive Queries over Trees |
GIS
2004
ACM
14 years 8 months ago
2004
ACM
Spatial, temporal and spatio-temporal aggregates over continuous streams of remotely sensed image data build a fundamental operation in many applications in the environmental scie...
CORR
2007
Springer
13 years 7 months ago
2007
Springer
We address the problem of answering Web ontology queries efficiently. An ontology is formalized as a Deductive Ontology Base (DOB), a deductive database that comprises the ontology...
PODS
2005
ACM
14 years 8 months ago
2005
ACM
In sensor networks, data acquisition frequently takes place at lowcapability devices. The acquired data is then transmitted through a hierarchy of nodes having progressively incre...
EDBT
2006
ACM
14 years 8 months ago
2006
ACM
Recent advances in hardware technology have resulted in the ability to collect and process large amounts of data. In many cases, the collection of the data is a continuous process ...
SIGMOD
2011
ACM
12 years 10 months ago
2011
ACM
In this paper we consider the problem of answering queries using views, which is important for data integration, query optimization, and data warehouses. We consider its simplest ...