151 search results - page 7 / 31 » On the Containment Problem for Queries in Conjunctive Form w... |
ACL
2003
13 years 9 months ago
2003
Standard IR systems can process queries such as “web NOT internet”, enabling users who are interested in arachnids to avoid documents about computing. The documents retrieved ...
PODS
2010
ACM
14 years 17 days ago
2010
ACM
We investigate a higher-order query language that embeds operators of the positive relational algebra within the simply-typed λ-calculus. Our language allows one to succinctly de...
PODS
2009
ACM
14 years 8 months ago
2009
ACM
We consider the problem of deciding query equivalence for a conjunctive language in which queries output complex objects composed from a mixture of nested, unordered collection ty...
PODS
1992
ACM
13 years 11 months ago
1992
ACM
: We study the problem of determining whether a given recursive Datalog program is equivalent to a given nonrecursive Datalog program. Since nonrecursive Datalog programs are equiv...
SIGIR
2012
ACM
11 years 10 months ago
2012
ACM
People are seldom aware that their search queries frequently mismatch a majority of the relevant documents. This may not be a big problem for topics with a large and diverse set o...