188 search results - page 4 / 38 » Query evaluation with soft-key constraints |
SIGMOD
2004
ACM
14 years 7 months ago
2004
ACM
We study the problem of answering queries through a target schema, given a set of mappings between one or more source schemas and this target schema, and given that the data is at...
ICEIS
2006
IEEE
14 years 1 months ago
2006
IEEE
The satisfiability test checks, whether or not the evaluation of a query returns the empty set for any input document, and can be used in query optimization for avoiding the submis...
IS
2007
13 years 7 months ago
2007
Preference queries are relational algebra or SQL queries that contain occurrences of the winnow operator (find the most preferred tuples in a given relation). Such queries are pa...
ICDT
1995
ACM
13 years 11 months ago
1995
ACM
Abstract. Extension of the relational database model to represent complex data has been a focus of much research in recent years. At the same time, an alternative extension of the ...
TDM
2004
13 years 8 months ago
2004
Document-centric XML collections contain text-rich documents, marked up with XML tags. The tags add lightweight semantics to the text. Querying such collections calls for a hybrid...