550 search results - page 43 / 110 » An Expressive Language for Linear Spatial Database Queries |
SIGIR
1996
ACM
14 years 27 days ago
1996
ACM
We present a deductive data model for concept-based query expansion. It is based abstraction levels: the conceptual, the expression and the occurrence level. Concepts and their re...
ICDT
1997
ACM
14 years 27 days ago
1997
ACM
Abstract. The goal of this paper is to study tractable iteration mechanisms for bags. The presence of duplicates in bags prevents iteration mechanisms developed in the context of s...
IFIP
2004
Springer
14 years 2 months ago
2004
Springer
In this paper we study the complexity of the model-checking problem for the tree logic introduced as the basis for the query language TQL [Cardelli and Ghelli, 2001]. We define tw...
ADBIS
1997
Springer
14 years 28 days ago
1997
Springer
A graphical formalized language is proposed for specifying systems of views over database schemas. The language is based on the notion of arrow (mapping) between data schemas and ...
GIS
2004
ACM
14 years 9 months ago
2004
ACM
Despite various interoperability recommendations, heterogeneity of Geographic Information Systems (GIS) is still an issue. This led to an increasing need for a data integration sy...