710 search results - page 20 / 142 » Relational Expressive Power of Constraint Query Languages |
RTA
2000
Springer
13 years 11 months ago
2000
Springer
Parallelism constraints are logical descriptions of trees. Parallelism constraints subsume dominance constraints and are equal in expressive power to context unification. Paralleli...
PODS
2008
ACM
14 years 7 months ago
2008
ACM
We consider the navigational core of XPath, extended with two operators: the Kleene star for taking the transitive closure of path expressions, and a subtree relativisation operat...
SOFSEM
2009
Springer
14 years 4 months ago
2009
Springer
Abstract. Constraint Handling Rules (CHR) is a general purpose, committedchoice declarative language which, differently from other similar languages, uses multi-headed (guarded) ru...
CIKM
2006
Springer
13 years 11 months ago
2006
Springer
By providing an integrated and optimized support for user-defined aggregates (UDAs), data stream management systems (DSMS) can achieve superior power and generality while preservi...
SP
1997
IEEE
13 years 12 months ago
1997
IEEE
A major drawback of existing access control systems is that they have all been developed with a specific access control policy in mind. This means that all protection requirement...