Call centers are at the core of today's customer relations management. Increasingly, they are also utilized internally as competence and knowledge centers. Turning them into service centers of the future (SCotF) requires parallel communication over several channels, including Internet services, in a distributed synchronous fashion. In this paper, we show that the emerging XML standards provide a good basis for this type of interaction. In turning e-service into a groupware application, we propose to apply a spatial awareness model to assist in the collaboration. We demonstrate that it can be integrated into the XML/XSL-framework. The results are compared with a previous solution, which applied proprietary tools. Questions of fidelity and a critique of the existing standards and tools complement the practical results.

Heapsort is an internal sorting method which sorts an array of n records in place in O(n log n) time. Heapsort is generally considered unsuitable for external random-access sorting. By replacing key comparisons with merge operations on pages, it is shown how to obtain an in-place external sort which requires O(m log m) page references, where m is the number of pages which the file occupies. The new sort method (called Hillsort) has several useful properties for advanced database management systems. Not only does Hillsort operate in place, i.e., no additional external storage space is required assuming that the page table can be kept in core memory, but accesses to adjacent pages in the heap require one seek only if the pages are physically contiguous. The authors define the Hillsort model of computation for external random-access sorting, develop the complete algorithm and then prove it correct. The model is next refined and a buffer management concept is introduced so as to reduce the number of merge operations and page references, and make the method competitive to a basic balanced two-way external merge. Performance characteristics are noted such as the worst-case upper bound, which can be carried over from Heapsort, and the average-case behavior, deduced from experimental findings. It is shown that the refined version of the algorithm which is on a par with the external merge sort.>

When sorting a multiset of N elements with n ≪ N distinct values, considerable savings can be obtained from an algorithm which sorts in time O(N log n) rather than O(N log N). In a previous paper, two Quicksort derivatives operating on linked lists were introduced which are stable, i.e., maintain the relative order of equal keys, and which achieve the previously unattainable lower bound in partition exchange sorting. Here, six more algorithms are presented which are unstable but operate on arrays. One of the algorithms is also designed for a speedup on presorted input. The algorithms are analyzed and compared to potential contenders in multiset sorting.

To sort an external file on a random access device, the merge sort is the generally accepted method. We present a new algorithm based on Quicksort which allows sorting of external files in situ. Analytical results and a comparison of test runs indicate that when the new algorithm is applied to a file with suitable key structure, it is competitive to the merge sort in terms of run-time behaviour.