Information Technology Reference
In-Depth Information
Interactively Eliciting Database Constraints and
Dependencies
Ravi Ramdoyal and Jean-Luc Hainaut
Laboratory of Database Application Engineering - PReCISE Research Centre
Faculty of Computer Science, University of Namur
Rue Grandgagnage 21 - B-5000 Namur, Belgium
{rra,jlh}@info.fundp.ac.be
http://www.fundp.ac.be/precise
Abstract.
When designing the conceptual schema of a future informa-
tion system, it is crucial to define a set of constraints that will guarantee
the consistency of the subsequent database once it is implemented and
operational. Eliciting and expressing such constraints and dependencies
is far from trivial, especially when end-users are involved and when there
is no directly usable data to play with. In this paper, we present an inter-
active process aimed to elicit hidden constraints such as value domains,
functional dependencies, attribute and role optionality and existence con-
straints. Inspired by the principles of Armstrong relations, it attempts to
acquire minimal data samples in order to validate declared constraints,
to elicit hidden constraints and to reject irrelevant constraints in concep-
tual schemas. This process is part of the RAINBOW approach, destined
to develop the data model of an information system based, among others,
on the reverse engineering of user-drawn form-based interfaces.
Keywords:
Information Systems Engineering, Requirements Engineer-
ing, Database Engineering, Electronic Forms Reverse Engineering,
Constraint Discovery.
1
Introduction
In the realm of Requirements engineering, Database engineering focuses on data
modelling, where the static data requirements are typically expressed by means
of a conceptual schema, which is an abstract view of the static objects of the
application domain. There are numerous types of constraints and dependencies
that can be established for such a schema. They can concern individual elements,
their components, or even how (the components of) an element can affect (the
components of) other elements. Traditional database elicitation techniques, such
as the analysis of corporate documents and interviews of stakeholders, usually
yield many relevant constraints during the design of the conceptual schema,
however some constraints may be forgotten, typically because the domain experts
were not aware of them, or (more probably) because they are part of some tacit
knowledge.
