59 search results - page 4 / 12 » Rewriting Unions of General Conjunctive Queries Using Views |
PODS
2003
ACM
14 years 7 months ago
2003
ACM
In this paper we consider general path constraints for semistructured databases. Our general constraints do not suffer from the limitations of the path constraints previously stud...
PVLDB
2010
13 years 5 months ago
2010
Virtual views are a mechanism that facilitates re-use and makes queries easier to express. However the use of iterative view definitions makes very simple query evaluation and an...
SIGMOD
1999
ACM
13 years 11 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 ...
SIGMOD
2004
ACM
14 years 7 months ago
2004
ACM
The prevalent use of XML highlights the need for a generic, flexible access-control mechanism for XML documents that supports efficient and secure query access, without revealing ...
IS
2012
12 years 3 months ago
2012
When transforming data one often wants certain information in the data source to be preserved, i.e., we identify parts of the source data and require these parts to be transformed...