99 search results - page 1 / 20 » On the complexity of division and set joins in the relationa... |
PODS
2005
ACM
14 years 5 months ago
2005
ACM
We show that any expression of the relational division operator in the relational algebra with union, difference, projection, selection, constant-tagging, and joins, must produce ...
ICDE
2006
IEEE
14 years 6 months ago
2006
IEEE
Relational division, also known as small divide, is a derived operator of the relational algebra that realizes a many-to-one set containment test, where a set is represented as a ...
MFDBS
1991
13 years 8 months ago
1991
We study an approach to relational databases which treats relations not as subsets of a Cartesian product but as subsets of some domain { a partially ordered space of descriptions...
PEPM
2010
ACM
14 years 1 months ago
2010
ACM
We show how to efficiently evaluate generic map-filter-product queries, generalizations of select-project-join (SPJ) queries in relational algebra, based on a combination of two...
AI
2008
Springer
13 years 5 months ago
2008
Springer
Local computation in join trees or acyclic hypertrees has been shown to be linked to a particular algebraic structure, called valuation algebra. There are many models of this alge...