After the Best paper award at the ER 2009 conference, we got invitation to write a journal article on Anchor Modeling. The title of the new article is “Anchor Modeling – Agile Information Modeling in Evolving Data Environmnets”. The authors are Lars Rönnbäck (Resight), Olle Regardt (Teracom), Maria Bergholtz (DSV), Paul Johannesson (DSV) and I. The article has now been accepted for publication in the journal Data and Knowledge Engineering (DKE, Elsevier). A preprint of it can be found here.
Abstract: Maintaining and evolving data warehouses is a complex, error prone, and time consuming activity. The main reason for this state of aairs is that the environment of a data warehouse is in constant change, while the
warehouse itself needs to provide a stable and consistent interface to information spanning extended periods
of time. In this article, we propose an agile information modeling technique, called Anchor Modeling, that
oers non-destructive extensibility mechanisms, thereby enabling robust and exible management of changes.
A key benet of Anchor Modeling is that changes in a data warehouse environment only require extensions,
not modications, to the data warehouse. Such changes, therefore, do not require immediate modications of
existing applications, since all previous versions of the database schema are available as subsets of the current
schema. Anchor Modeling decouples the evolution and application of a database, which when building a
data warehouse enables shrinking of the initial project scope. While data models were previously made
to capture every facet of a domain in a single phase of development, in Anchor Modeling fragments can
be iteratively modeled and applied. We provide a formal and technology independent denition of anchor
models and show how anchor models can be realized as relational databases together with examples of
schema evolution. We also investigate performance through a number of lab experiments, which indicate that
under certain conditions anchor databases perform substantially better than databases constructed using
traditional modeling techniques.
Keywords: Anchor Modeling, database modeling, normalization, 6NF, data warehousing, agile development,
temporal databases, table elimination
