54 search results - page 4 / 11 » Some properties of the disjunctive languages contained in Q |
ICDT
2009
ACM
14 years 7 months ago
2009
ACM
The class of unions of conjunctive queries (UCQ) has been shown to be particularly well-behaved for data exchange; its certain answers can be computed in polynomial time (in terms...
LICS
2009
IEEE
14 years 28 days ago
2009
IEEE
Weighted automata are nondeterministic automata with numerical weights on transitions. They can define quantitative languages L that assign to each word w a real number L(w). In ...
ECAI
1994
Springer
13 years 10 months ago
1994
Springer
Abstract. Many recent works point out that there are several possibilities of assigning a meaning to a concept definition containing some sort of recursion. In this paper, we argue...
SIGMOD
1999
ACM
13 years 10 months ago
1999
ACM
We address the problem of query rewriting for TSL, a language for querying semistructured data. We develop and present an algorithm that, given a semistructured query q and a set ...
ICDT
1995
ACM
13 years 9 months ago
1995
ACM
Partial information in databases can arise when information from several databases is combined. Even if each database is complete for some \world", the combined databases wil...