126 search results - page 13 / 26 » The Complexity of Acyclic Conjunctive Queries |
EDBT
2008
ACM
14 years 7 months ago
2008
ACM
In this paper we study the problem of mining all frequent queries in a given database table, a problem known to be intractable even for conjunctive queries. We restrict our attent...
ICDT
2003
ACM
14 years 23 days ago
2003
ACM
All the languages for querying semistructured data and the web use as an integral part regular expressions. Based on practical observations, finding the paths that satisfy those r...
DBPL
2005
Springer
2005
Springer
Complexity and Approximation of Fixing Numerical Attributes in Databases Under Integrity Constraints
14 years 1 months ago
Consistent query answering is the problem of computing the answers from a database that are consistent with respect to certain integrity constraints that the database as a whole ma...
FOCS
2003
IEEE
14 years 25 days ago
2003
IEEE
We give a complexity theoretic classification of homomorphism problems for graphs and, more generally, relational structures obtained by restricting the left hand side structure ...
VLDB
2005
ACM
14 years 1 months ago
2005
ACM
Existing work for query processing over graph data models often relies on pre-computing the transitive closure or path indexes. In this paper, we propose a family of stack-based a...