Estimating the number of distinct values is a wellstudied problem, due to its frequent occurrence in queries and its importance in selecting good query plans. Previous work has sh...
Approximate query answering systems provide very fast alternatives to OLAP systems when applications are tolerant to small errors in query answers. Current sampling-based approach...
A multidimensional database can be seen as a collection of multidimensional cubes, from which information is usually extracted by aggregation; aggregated data can be calculated ei...
An important issue in data warehouse development is the selection of a set of views to materialize in order to accelerate OLAP queries, given certain space and maintenance time co...
Abstract. In many cases, users may want to consider incomplete answers to their queries. Often, however, there is an overwhelming number of such answers, even if subsumed answers a...