Sciweavers

4397 search results - page 190 / 880
» Relational Algebra Operations
Sort
View
SIGMOD
2009
ACM
220views Database» more  SIGMOD 2009»
16 years 3 months ago
Keyword search in databases: the power of RDBMS
Keyword search in relational databases (RDBs) has been extensively studied recently. A keyword search (or a keyword query) in RDBs is specified by a set of keywords to explore the...
Lu Qin, Jeffrey Xu Yu, Lijun Chang
96
Voted
LICS
2006
IEEE
15 years 9 months ago
A Characterisation of First-Order Constraint Satisfaction Problems
Abstract. We describe simple algebraic and combinatorial characterisations of finite relational core structures admitting finitely many obstructions. As a consequence, we show th...
Benoit Larose, Cynthia Loten, Claude Tardif
ATVA
2005
Springer
80views Hardware» more  ATVA 2005»
15 years 9 months ago
Syntactical Colored Petri Nets Reductions
Abstract. In this paper, we develop a syntactical version of elaborated reductions for high-level Petri nets. These reductions simplify the model by merging some sequential transit...
Sami Evangelista, Serge Haddad, Jean-Franço...
135
Voted
LICS
1994
IEEE
15 years 7 months ago
Subtyping and Parametricity
In this paper we study the interaction of subtyping and parametricity. We describe a logic for a programming language with parametric polymorphism and subtyping. The logic support...
Gordon D. Plotkin, Martín Abadi, Luca Carde...
118
Voted
DEXA
1994
Springer
92views Database» more  DEXA 1994»
15 years 7 months ago
OR-SML: A Functional Database Programming Language for Disjunctive Information and Its Applications
We describe a functional database language OR-SML for handling disjunctive information in database queries, and its implementation on top of Standard ML 12]. The core language has ...
Elsa L. Gunter, Leonid Libkin