Editing External sorting (section)

{{short description|Class of sorting algorithms that can handle massive amounts of data}}
[[File:External_sorting_algorithm.png|thumb|right|external sorting algorithm]]
'''External sorting''' is a class of [[sorting algorithm]]s that can handle massive amounts of [[data]]. External sorting is required when the data being sorted do not fit into the [[main memory]] of a computing device (usually [[RAM]]) and instead they must reside in the slower [[Auxiliary memory|external memory]], usually a [[disk drive]]. Thus, external sorting algorithms are [[external memory algorithm]]s and thus applicable in the [[external memory model|external memory]] [[model of computation]].

External sorting algorithms generally fall into two types, distribution sorting, which resembles [[quicksort]], and external merge sort, which resembles [[merge sort]]. External merge sort typically uses a [[hybrid algorithm|hybrid]] sort-merge strategy.  In the sorting phase, chunks of data small enough to fit in main memory are read, sorted, and written out to a temporary file.  In the merge phase, the sorted subfiles are combined into a single larger file.