62 search results - page 6 / 13 » Containment of Conjunctive Queries over Databases with Null ... |
DLOG
2008
13 years 9 months ago
2008
The paper addresses the problem of explaining some reasoning tasks associated with the DL-Lite Description Logic. Because of the simplicity of the language, standard concept level ...
ICDT
2012
ACM
11 years 9 months ago
2012
ACM
Previous studies of incomplete XML documents have identified three main sources of incompleteness – in structural information, data values, and labeling – and addressed data ...
SIGMOD
2005
ACM
14 years 15 days ago
2005
ACM
One of the most powerful features of SQL is the use of nested queries. Most research work on the optimization of nested queries focuses on aggregate subqueries. However, the solut...
SIGMOD
2011
ACM
12 years 9 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...
ADBIS
2003
Springer
13 years 10 months ago
2003
Springer
Abstract. Set-valued attributes are convenient to model complex objects occurring in the real world. Currently available database systems support the storage of set-valued attribut...