777 search results - page 94 / 156 » Optimization of Relational Preference Queries |
220
Voted
PODS
2009
ACM
16 years 3 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...
125
Voted
PODS
1999
ACM
15 years 7 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...
121
Voted
SIGMOD
2004
ACM
16 years 2 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,...
125
Voted
WLP
2000
Springer
15 years 6 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...
135
Voted
ER
2008
Springer
15 years 4 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 ...