ICDT
2012
ACM
11 years 6 months ago
2012
ACM
We introduce a representation system for relational data based on algebraic factorisation using distributivity of product over union and commutativity of product and union. We giv...
PODS
2012
ACM
11 years 6 months ago
2012
ACM
Over the past several decades, the study of conjunctive queries has occupied a central place in the theory and practice of database systems. In recent years, conjunctive queries h...
PODS
2012
ACM
11 years 6 months ago
2012
ACM
Data is increasingly being bought and sold online, and Webbased marketplace services have emerged to facilitate these activities. However, current mechanisms for pricing data are ...
IS
2012
11 years 12 months ago
2012
When transforming data one often wants certain information in the data source to be preserved, i.e., we identify parts of the source data and require these parts to be transformed...
CIKM
2011
Springer
12 years 4 months ago
2011
Springer
We present Nyaya, a system for the management of Semantic-Web data which couples a general-purpose and extensible storage mechanism with efficient ontology reasoning and querying ...
SIGMOD
2011
ACM
12 years 7 months ago
2011
ACM
Probabilistic database systems have successfully established themselves as a tool for managing uncertain data. However, much of the research in this area has focused on efficient...
DLOG
2011
12 years 7 months ago
2011
We show that, although conjunctive queries over OWL 2 QL ontologies are reducible to database queries, no algorithm can construct such a reduction in polynomial time without changi...
EUSFLAT
2009
13 years 2 months ago
2009
This paper proposes an approach aimed at obviating empty answers for a family of conjunctive queries involving Boolean or fuzzy value constraints. Contrary to the approaches based ...
ADBIS
2009
Springer
13 years 2 months ago
2009
Springer
We consider the problem of selecting views and indexes that minimize the evaluation costs of the important queries under an upper bound on the disk space available for storing the ...
RR
2010
Springer
13 years 2 months ago
2010
Springer
Based on practical observations on rule-based inference on RDF data, we study the problem of redundancy elimination on RDF graphs in the presence of rules (in the form of Datalog r...