Talks and Poster Presentations (with Proceedings-Entry):
P. Guagliardo, R. Pichler, E. Sallinger:
"Enhancing the Updatability of Projective Views";
Talk: AMW - Alberto Mendelzon International Workshop on Foundations of Data Management,
- 2013-05-23; in: "Proceedings of the 7th Alberto Mendelzon International Workshop on Foundations of Data Management",
CEUR Workshop Proceedings,
Updating a database by means of a set of views is a classical problem in database
research, known as the view update problem. It consists in "pushing back" the
changes introduced into view relations by an update to the underlying database
relations over which the view relations are de ned. In very recent years, the view
update problem has received renewed interest and attention.
View updates can be consistently and univocally propagated under the con-
dition that the mapping between database and view relations is
lossless, that is, the views provide the same amount of information as the database
itself. Clearly,this is quite a strong requirement, as in common practical scenarios user views
are created with the aim of allowing access only to speci c portions of the data-
base and thus, being lossy by design, such views are not directly updatable. The
solution to this problem consists in using additional information, transferred by
a so-called view complement, that is missing from the original view but needed
to propagate the updates. However, under what is known as the constant complement principle, this complementary information must be invariant during the update process, that is, it must not be modi ed directly or indirectly by
the view update. Therefore, the amount of information transferred by the view
complement should be kept as small as possible.
To the best of our knowledge, in the relational setting, the only case studied
in the literature is the one where the initial view consists of a single projection
and the complement to be constructed is also restricted to a single projection .
A natural extension of the above, not investigated so far, is the case in which we
are given a view as a set of projections and we want to construct a complement
that consists of a set of projections too. The goal of our work is to initiate the
generalization of the study of view complements in this direction.
information integration, updates
Electronic version of the publication:
Project Head Reinhard Pichler:
Heterogene Information Integration
Created from the Publication Database of the Vienna University of Technology.