View materialization has been shown to ameliorate the scalability problem of data-intensiveweb servers. However, unlike data warehouses which are off-line during updates, most web servers maintain their back-end databases online and perform updates concurrently with user accesses. In such environments, the selection of views to materialize must be performed online; both performance and data fre...

To fulfill the requirement of fast interactive multidimensional data analysis, database systems precompute aggregate views on some subsets of dimensions and their corresponding hierarchies. However, the problem of what to precompute is difficult and intriguing. The leading existing algorithm, BPUS, has a running time that is polynomial in the number of views and is guaranteed to be within (0.63...