59 search results - page 9 / 12 » Rewriting Unions of General Conjunctive Queries Using Views |
VLDB
1995
ACM
13 years 9 months ago
1995
ACM
In this paper we introduce generalized projections (GPs), an extension of duplicateeliminating projections, that capture aggregations, groupbys, duplicate-eliminating projections ...
ICDE
2005
IEEE
14 years 7 months ago
2005
IEEE
Data warehousing and on-line analytical processing (OLAP) are essential for decision support applications. Common OLAP operations include for example drill down, roll up, pivot an...
ICDT
2007
ACM
13 years 12 months ago
2007
ACM
Abstract. We define and study formal privacy guarantees for information integration systems, where sources are related to a public schema by mappings given by source-to-target dep...
DAWAK
1999
Springer
13 years 10 months ago
1999
Springer
A data warehouse DW can be seen as a set of materialized views de ned over remote base relations. When a query is posed, it is evaluated locally, using the materialized views, wi...
AAAI
2007
13 years 8 months ago
2007
Expressive Description Logics (DLs) have been advocated as formalisms for modeling the domain of interest in various application areas. An important requirement is the ability to ...