151 search results - page 5 / 31 » On the Containment Problem for Queries in Conjunctive Form w... |
EDBT
2002
ACM
14 years 7 months ago
2002
ACM
The problem of finding contained rewritings of queries using views is of great importance in mediated data integration systems. In this paper, we first present a general approach f...
FOCS
1998
IEEE
13 years 11 months ago
1998
IEEE
This paper deals with the evaluation of acyclic Boolean conjunctive queries in relational databases. By well-known results of Yannakakis [1981], this problem is solvable in polynom...
PODS
2010
ACM
14 years 17 days ago
2010
ACM
Both semantic and type-based query optimization rely on the idea that queries often exhibit non-trivial rewritings if the state space of the database is restricted. Despite their ...
ICDT
2012
ACM
11 years 10 months ago
2012
ACM
A universal model of a database D and a set Σ of integrity constraints is a database that extends D, satisfies Σ, and is most general in the sense that it contains sound and co...
DEDUCTIVE
1994
13 years 8 months ago
1994
Given an intensional database (IDB) and an extension database (EDB), the view update problem translates updates on the IDB into updates on the EDB. One approach to the view update...