Most of work on partial information in databases asks which operations of standard languages, like relational algebra, can still be performed correctly in the presence of nulls. In...
In this paper we discuss two data models for spatial database systems: the linear data model and the topological data model. Both can be used to model a wide range of applications....
Database transformations arise in many di erent settings including database integration, evolution of database systems, and implementing user views and data-entry tools. This paper...
Constraint management plays an important role in design applications where constraints re ect design restrictions and design decisions. ECA rules are a widely used mechanism to enf...
Engineering applications that use Active DBMSs (ADBMSs) often need to group activities into modes that are shifted during the execution of different tasks. This paper presents a me...
During the last decade various spatial data structures have been designed and compared against each other with respect to their performance. Still missing is a lower bound result,...
Databases are often incomplete because of the presence of disjunctive information, due to con icts, partial knowledge and other reasons. Queries against such databases often ask q...