151 search results - page 3 / 31 » On the Containment Problem for Queries in Conjunctive Form w... |
DBPL
2007
Springer
14 years 1 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...
ER
2008
Springer
13 years 9 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 ...
INLG
2004
Springer
14 years 25 days ago
2004
Springer
Abstract. We present a new approach to the generation of referring expressions containing attributive, type and relational properties combined by conjunctions, disjunctions and neg...
PODS
2004
ACM
14 years 7 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...
PVLDB
2010
13 years 5 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...