Computing multidimensional aggregates in high dimensions is a performance bottleneck for many OLAP applications. Obtaining the exact answer to an aggregation query can be prohibit...
The general problem of answering top-k queries can be modeled using lists of data items sorted by their local scores. The most efficient algorithm proposed so far for answering to...
Severalmethodshavebeenproposedto compile recursive Datalog programs. The most well-known perform a rewriting of rules using MAGIC or PROBLEM predicates in order to push selections...
We study the complexity of the problem of answering queries using materialized views. This problem has attracted a lot of attention recently because of its relevance in data integ...
In an on-line statistical database, the query system should leave unanswered queries asking for sums that could lead to the disclosure of confidential data. To check that, every su...