492 search results - page 56 / 99 » Computing aggregations in database query languages |
SIGCSE
2005
ACM
14 years 3 months ago
2005
ACM
Universities are increasingly offering courses online. Feedback, assessment, and guidance are important features of this online courseware. Together, in the absence of a human tut...
FOCS
1998
IEEE
14 years 2 months ago
1998
IEEE
This paper deals with the evaluation of acyclic Boolean conjunctive queries in relational databases. By well-known results of Yannakakis [1981], this problem is solvable in polynom...
GIS
2010
ACM
13 years 8 months ago
2010
ACM
This paper proposes an efficient, decentralized algorithm for determining the topological relationship between two regions monitored by a geosensor network. Many centralized algo...
EDBT
2000
ACM
14 years 1 months ago
2000
ACM
OLAP applications use precomputation of aggregate data to improve query response time. While this problem has been well-studied in the recent database literature, to our knowledge ...
DOOD
1995
Springer
14 years 1 months ago
1995
Springer
Wrappers provide access to heterogeneous information sources by converting application queries into source speci c queries or commands. In this paper we present a wrapper implemen...