The design of external index structures for one- and multidimensional extended objects is a long and well studied subject in basic database research. Today, more and more commercia...
We rework parts of the classical relational theory when the underlying domain is a structure with some interpreted operations that can be used in queries. We identify parts of the...
Information integration systems have to cope with the different and limited query interfaces of the underlying information sources. First, the integration systems need description...
The accurate formulation of boolean expressions is a notorious problem in programming languages and database query tools. This paper studies the ways that untrained users naturall...
In previous papers we have proposed a graphical query language for expressing traversal recursions in labelled, directed graphs. A fundamental feature of the language is the use o...