We study the problem of answering queries over sources with limited access patterns. The problem is to decide whether a given query Q is feasible, i.e., equivalent to an executable...
All the languages for querying semistructured data and the web use as an integral part regular expressions. Based on practical observations, finding the paths that satisfy those r...
Answering queries posed over knowledge bases is a central problem in knowledge representation and database theory. In databases, query containment is one of the important query op...
Given a record set D and a query score function F, a top-k query returns k records from D, whose values of function F on their attributes are the highest. In this paper, we investi...
Semantic query optimization can dramatically speed up database query answering by knowledge intensive reformulation. But the problem of how to learn required semantic rules has no...