Abstract A new sort algorithm, called AlphaSort, demonstrates that commodity processors and disks can handle commercial batch workloads. Using Alpha AXP processors, commodi ~ memory, and arrays of SCSI disks, AlphaSort runs the industry-standard sort benchmark in seven seconds. This beats the best published record on a 32-cpu 32-disk Hypercube by 8:1. On another benchmark, AlphaSort sorted more than a gigabyte in a minute. AlphaSort is a cache-sensitive memory-intensive sort algorithm. It uses file striping to get high disk bandwidth. It uses QuickSort to generate runs and uses replacementselection to merge the runs. It uses shared memoq multiprocessors to break the sort into subsort chores. Because startup times are becoming a sign~icant part of the total time, we propose two new benchmarks:

A new sort algorithm, called AlphaSort, demonstrates that commodity processors and disks can handle commercial batch workloads. Using commodity processors, memory, and arrays of SCSI disks, AlphaSort runs the industry-standard sort benchmark in seven seconds. This beats the best published record on a 32-CPU 32-disk Hypercube by 8:1. On another benchmark, AlphaSort sorted more than a gigabyte in a minute. AlphaSort is a

External mergesort is normally implemented so that each run is stored contiguously on disk and blocks of data are read exactly in the order they are needed during merging. We investigate two ideas for improving the performance of external mergesort: interleaved layout and a new reading strategy. Interleaved layout places blocks from different runs in consecutive disk addresses. This is done in the hope that interleaving will reduce seek overhead during merging. The new reading strategy precomputes the order in which data blocks are to be read according to where they are located on disk and when they are needed for merging. Extra buffer space makes it possible to read blocks in an order that reduces seek overhead, instead of reading them exactly in the order they are needed for merging. A detailed simulation model was used to compare the two layout strategies and three reading strategies. The effects of using multiple work disks were also investigated. We found that, in most cases, inte...

: NTsort is an external sort on WindowsNT 5.0. It has minimal functionality but excellent price performance. In particular, running on mail-order hardware it can sort 1.5 GB for a penny. NT5.0 is not yet available. For commercially available sorts, Postman Sort from Robert Ramey Software Development has elapsed time performance comparable to NTsort, while using less processor time. It can sort 1.27 GB for a penny (12.7 million records.) These sorts set new price-performance records. This paper documents this and proposes that the PennySort benchmark be revised to Performance/Price sort: a simple GB/$ sort metric based on a two-pass external sort. Why does anyone care about sorting and sort performance? The prosaic reason is that sorting is a common task -- it is frequently used in database systems, data analysis, and data mining. Another important reason is that sorting is a simple balanced workload, involving memory access, IO, and cpu. It evaluates a computer system's overall perfor...