66 search results - page 1 / 14 » Conjunctive Query Containment over Trees |
DBPL
2007
Springer
13 years 11 months ago
2007
Springer
Abstract. The complexity of containment and satisfiability of conjunctive queries over finite, unranked, labeled trees is studied with respect to the axes Child, NextSibling, the...
ICDT
2007
ACM
13 years 11 months ago
2007
ACM
Abstract. We study containment of conjunctive queries that are evaluated over databases that may contain tuples with null values. We assume the semantics of SQL for single block qu...
DASFAA
2006
IEEE
13 years 11 months ago
2006
IEEE
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 ...