Given a dataset P and a preference function f, a top-k query retrieves the k tuples in P with the highest scores according to f. Even though the problem is well-studied in convent...
Most relational query optimizers make use of information about the costs of accessing tuples and data structures on various storage devices. This information can at times be off b...
This paper addresses the problem of evaluating ranked top-? queries with expensive predicates. As major DBMSs now all support expensive user-defined predicates for Boolean queries...
To effectively support today's global economy, database systems need to store and manipulate text data in multiple languages simultaneously. Current database systems do suppor...
Peer Data Management Systems (PDMSs) have been introduced as a solution to the problem of large-scale sharing of semantically rich data. A PDMS consists of semantic peers connecte...