62 search results - page 2 / 13 » Containment of Conjunctive Queries over Databases with Null ... |
SEBD
2007
13 years 6 months ago
2007
We consider the problem of query containment over an object data model derived from F-logic. F-logic has generated considerable interest commercially, in the academia, and within ...
ER
2008
Springer
13 years 6 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 ...
PODS
2004
ACM
14 years 4 months ago
2004
ACM
The problem of deciding query containment has important applications in classical query optimization and heterogeneous database systems. Query containment is undecidable for unres...
PODS
2000
ACM
13 years 9 months ago
2000
ACM
The problem of query containment is fundamental to many aspects of database systems, including query optimization, determining independence of queries from updates, and rewriting ...
ICDT
2012
ACM
11 years 7 months ago
2012
ACM
A universal model of a database D and a set Σ of integrity constraints is a database that extends D, satisfies Σ, and is most general in the sense that it contains sound and co...