777 search results - page 94 / 156 » Optimization of Relational Preference Queries |
PODS
2009
ACM
14 years 10 months ago
2009
ACM
Let be a finite, ordered alphabet, and consider a string x = x1x2 . . . xn n . A secondary index for x answers alphabet range queries of the form: Given a range [al, ar] , retu...
PODS
1999
ACM
14 years 2 months ago
1999
ACM
One of the most important types of query processing in spatial databases and geographic information systems is the spatial join, an operation that selects, from two relations, all...
SIGMOD
2004
ACM
14 years 10 months ago
2004
ACM
Current day database applications, with large numbers of users, require fine-grained access control mechanisms, at the level of individual tuples, not just entire relations/views,...
WLP
2000
Springer
14 years 1 months ago
2000
Springer
In this paper, a dynamic approach to deductive query evaluation is presented which combines the e ects of di erent SIP strategies used for the magic set rewriting technique. Given...
ER
2008
Springer
13 years 12 months ago
2008
Springer
Access limitations may occur when querying data sources over the web or heterogeneous data sources presented as relational tables: this happens, for instance, in Data Exchange and ...