412 search results - page 41 / 83 » Aggregate queries over ontologies |
DC
2008
13 years 10 months ago
2008
We study the problem of maintaining a sketch of recent elements of a data stream. Motivated by applications involving network data, we consider streams that are asynchronous, in wh...
ICDE
2005
IEEE
14 years 11 months ago
2005
IEEE
Online monitoring of data streams poses a challenge in many data-centric applications, such as telecommunications networks, traffic management, trend-related analysis, webclick st...
ICDE
2005
IEEE
14 years 11 months ago
2005
IEEE
Efficient one-pass computation of F0, the number of distinct elements in a data stream, is a fundamental problem arising in various contexts in databases and networking. We consid...
ERCIMDL
2007
Springer
14 years 4 months ago
2007
Springer
Abstract. In this paper we present an approach to question answering over heterogeneous knowledge sources that makes use of different ontology management components within the sce...
SIGMOD
2007
ACM
14 years 10 months ago
2007
ACM
This paper describes query processing in the DBO database system. Like other database systems designed for ad-hoc, analytic processing, DBO is able to compute the exact answer to ...