251 search results - page 2 / 51 » Rewriting Aggregate Queries using Description Logic |
ICDT
2005
ACM
14 years 1 months ago
2005
ACM
d abstract) Foto Afrati1 and Rada Chirkova2 1 Electrical and Computing Eng., National Technical University of Athens, 157 73 Athens, Greece 2 Computer Science Department, North Car...
DLOG
2007
13 years 10 months ago
2007
We present cq-programs, which enhance nonmonotonic description logics (dl-) programs by conjunctive queries (CQ) and union of conjunctive queries (UCQ) over Description Logics kno...
CIKM
2008
Springer
13 years 9 months ago
2008
Springer
Answering queries over ontologies is an important issue for the Semantic Web. Aggregate queries were widely studied for relational databases but almost no results are known for ag...
SIGMOD
2006
ACM
14 years 7 months ago
2006
ACM
We study the problem of finding efficient equivalent viewbased rewritings of relational queries, focusing on query optimization using materialized views under the assumption that ...
VLDB
1995
ACM
13 years 11 months ago
1995
ACM
In this paper we introduce generalized projections (GPs), an extension of duplicateeliminating projections, that capture aggregations, groupbys, duplicate-eliminating projections ...