Sciweavers

DLOG
2006
13 years 5 months ago
Data Complexity of Answering Unions of Conjunctive Queries in SHIQ
The novel context of accessing and querying large data repositories through ontologies that are formalized in terms of expressive DLs requires on the one hand to consider query an...
Magdalena Ortiz, Diego Calvanese, Thomas Eiter
PODS
2010
ACM
159views Database» more  PODS 2010»
13 years 5 months ago
On probabilistic fixpoint and Markov chain query languages
We study highly expressive query languages such as datalog, fixpoint, and while-languages on probabilistic databases. We generalize these languages such that computation steps (e....
Daniel Deutch, Christoph Koch, Tova Milo
ICDE
2008
IEEE
166views Database» more  ICDE 2008»
14 years 5 months ago
A Clustered Index Approach to Distributed XPath Processing
Supporting top-k queries over distributed collections of schemaless XML data poses two challenges. While XML supports expressive query languages such as XPath and XQuery, these la...
Georgia Koloniari, Evaggelia Pitoura