121 search results - page 13 / 25 » On Containment of Conjunctive Queries with Negation |
AAAI
2012
11 years 10 months ago
2012
We tackle the problem of defining a well-founded semantics (WFS) for Datalog rules with existentially quantified variables in their heads and negations in their bodies. In partic...
VLDB
2006
ACM
14 years 8 months ago
2006
ACM
In this paper we study the following problem. Given a database and a set of queries, we want to find a set of views that can compute the answers to the queries, such that the amoun...
SOFSEM
2010
Springer
14 years 4 months ago
2010
Springer
Abstract. This article introduces KWQL, spoken “quickel”, a rulebased query language for a semantic wiki based on the label-keyword query paradigm. KWQL allows for rich combine...
SIGMOD
2006
ACM
14 years 7 months ago
2006
ACM
We study the problem of finding efficient equivalent viewbased rewritings of relational queries, focusing on query optimization using materialized views under the assumption that ...
SIGMOD
2009
ACM
14 years 8 months ago
2009
ACM
Composite (or Complex) event processing (CEP) systems search sequences of incoming events for occurrences of userspecified event patterns. Recently, they have gained more attentio...