This book presents a collection of coordinated scientific
papers describing the work conducted and the results
achieved within the LOGIDATA+ project, a research action
funded by the Italian national research council CNR.
Theaim of the LOGIDATA+ project is the definition of
advanced database systems which significantly extend the
functionalities of the current systems, with specific
reference to the application areas for which relational
systemsare not considered satisfactory. These new systems
will allow the definitionof data with complex structures,
the representation of semantic relationships between
objects, and the use of powerful query and update languages.
They will be based on a combination of techniques
originatingfrom relational databases and logic programming,
with contributions from object-oriented programming.
The goal of the LOGIDATA+ project is the design, definition,
and prototype implementation of a database management system
with complex structures and a class hierarchy, to be
accessed through a rule-based language. This book presents
an integrated view of the project at the end of the first
phase. The second phase will be mainly concerned with the
implementation of prototypes.