357 search results - page 15 / 72 » An Algebraic Approach to the Complexity of Generalized Conju... |
WWW
2011
ACM
13 years 2 months ago
2011
ACM
The problem of answering SPARQL queries over virtual SPARQL views is commonly encountered in a number of settings, including while enforcing security policies to access RDF data, ...
PODS
2007
ACM
14 years 8 months ago
2007
ACM
We show that relational algebra calculations for incomplete databases, probabilistic databases, bag semantics and whyprovenance are particular cases of the same general algorithms...
EDBT
2008
ACM
14 years 8 months ago
2008
ACM
Data exchange is the problem of transforming data structured under a schema (called source) into data structured under a different schema (called target). The emphasis of data exc...
PODS
2010
ACM
14 years 1 months ago
2010
ACM
Both semantic and type-based query optimization rely on the idea that queries often exhibit non-trivial rewritings if the state space of the database is restricted. Despite their ...
VLDB
2006
ACM
14 years 8 months ago
2006
ACM
While the information published in the form of XML-compliant documents keeps fast mounting up, efficient and effective query processing and optimization for XML have now become mor...