143 search results - page 18 / 29 » Query Order and the Polynomial Hierarchy |
106
click to vote
DBPL
1993
Springer
15 years 1 months ago
1993
Springer
In this paper we study the expressive power of query languages for nested bags. We de ne the ambient bag language by generalizing the constructs of the relational language of Brea...
EDBT
2009
ACM
15 years 1 months ago
2009
ACM
We propose efficient techniques for processing various TopK count queries on data with noisy duplicates. Our method differs from existing work on duplicate elimination in two sign...
JACM
2000
14 years 9 months ago
2000
We rework parts of the classical relational theory when the underlying domain is a structure with some interpreted operations that can be used in queries. We identify parts of the...
111
click to vote
EDBT
2011
ACM
14 years 28 days ago
2011
ACM
Data integration systems offer users a uniform interface to a set of data sources. Previous work has typically assumed that the data sources are independent of each other; however...
DEXA
1995
Springer
15 years 29 days ago
1995
Springer
Abstract. The object-oriented database management systems store references to objects (implicit joins, precomputed joins), and use path expressions in query languages. One way of e...