unsorted

Unsorted describes data or items that have not been arranged according to a defined order or criterion. In computing and data processing, unsorted collections may include arrays, lists, records, or directories that do not adhere to a specific sorting key, such as numeric ascending order or lexicographic order. The term contrasts with sorted and partially sorted data, where elements follow a particular order.

In computer science, an unsorted array generally requires linear search, with time proportional to the number of elements. Sorting algorithms can be used to convert unsorted data into a defined order, enabling faster searches and ordered output. Common sorting methods include quicksort, mergesort, and heapsort, each with different performance characteristics depending on data size and structure.

Real-world data processing often involves unsorted data. File systems may present directory entries in an arbitrary sequence unless a sort option is used. Database queries may return rows in unspecific order unless an ORDER BY clause is provided. Streaming data may arrive unsorted and be buffered for on-demand sorting or indexed processing.

Techniques for handling unsorted data include in-memory sorting, external sorting for large datasets, and maintaining auxiliary structures such as indexes to enable efficient access without repeatedly sorting the entire dataset. The decision to sort depends on factors such as data size, required response time, and the frequency of updates.

See also: Sorting, Search algorithms, Data structures.