SIGMOD
1999
ACM
14 years 3 months ago
1999
ACM
In this paper we present a mechanism for translating constraint queries, i.e., Boolean expressions of constraints, across heterogeneous information sources. Integrating such syste...
GEOS
2009
Springer
14 years 4 months ago
2009
Springer
Abstract. Often the information present in a spatial knowledge base is represented at a different level of granularity and abstraction than the query constraints. For querying onto...