33 search results - page 2 / 7 » When is the evaluation of conjunctive queries tractable |
AMW
2010
13 years 7 months ago
2010
We address the problem of answering conjunctive queries over knowledge bases, specified by sets of first-order sentences called tuple-generating dependencies (TGDs). This problem i...
PVLDB
2010
13 years 4 months ago
2010
Probabilistic databases hold promise of being a viable means for large-scale uncertainty management, increasingly needed in a number of real world applications domains. However, q...
EDBT
2006
ACM
14 years 6 months ago
2006
ACM
Scientific data in the life sciences is distributed over various independent multi-format databases and is constantly expanding. We discuss a scenario where a life science research...
ER
2008
Springer
13 years 8 months ago
2008
Springer
Access limitations may occur when querying data sources over the web or heterogeneous data sources presented as relational tables: this happens, for instance, in Data Exchange and ...
PVLDB
2010
13 years 4 months ago
2010
Virtual views are a mechanism that facilitates re-use and makes queries easier to express. However the use of iterative view definitions makes very simple query evaluation and an...