99 search results - page 3 / 20 » On the complexity of division and set joins in the relationa... |
IJAC
2002
13 years 5 months ago
2002
Abstract. We discuss the computational complexity of several problems concerning subsets of an algebraic structure that generate the structure. We show that the problem of determin...
PODS
1999
ACM
13 years 10 months ago
1999
ACM
We give a polymorphic account of the relational algebra. We introduce a formalism of \type formulas" speci cally tuned for relational algebra expressions, and present an algo...
DEBS
2007
ACM
13 years 9 months ago
2007
ACM
Queries for composite events typically involve the four complementary dimensions of event data, event composition, relationships between events (esp. temporal and causal), and acc...
TKDE
2012
11 years 8 months ago
2012
—Preparing a data set for analysis is generally the most time consuming task in a data mining project, requiring many complex SQL queries, joining tables and aggregating columns....
FLAIRS
2007
13 years 8 months ago
2007
In this paper we shall introduce an approach that forms a basis for temporal data mining. A relation algebra is applied for the purpose of representing simultaneously dependencies...