204 search results - page 6 / 41 » Containment of Conjunctive Queries with Negation: Algorithms... |
PODS
2003
ACM
15 years 9 months ago
2003
ACM
In this paper we study the following problem. Given a database and a set of queries, we want to find, in advance, a set of views that can compute the answers to the queries, such ...
61
Voted
JCSS
2008
14 years 9 months ago
2008
We give a quadratic algorithm for the following structure identification problem: given a Boolean relation R and a finite set S of Boolean relations, can the relation R be express...
EDBT
2006
ACM
15 years 9 months ago
2006
ACM
Current methods for selectivity estimation fall into two broad categories, synopsis-based and sampling-based. Synopsis-based methods, such as histograms, incur minimal overhead at ...
ICASSP
2011
IEEE
14 years 1 months ago
2011
IEEE
1 Query-by-example information retrieval provides users a flexible but efficient way to accurately describe their information needs. The query exemplars are usually long and in th...
VLDB
1997
ACM
15 years 1 months ago
1997
ACM
Efficient user-adaptable similarity search more and more increases in its importance for multimedia and spatial database systems. As a general similarity model for multi-dimension...