Reverse index

<p><a href="/facts/Database_management_systems/VYcpkevb">Database management systems</a> provide multiple types of <a href="/facts/Index_(database)/TRqmk9It">indexes</a> to improve performance and data integrity across diverse applications. Index types include <a href="/facts/B-tree/IHE2l8GR">b-trees</a>, <a href="/facts/Bitmap_index/2zkCovb8">bitmaps</a>, and <a href="/facts/R-tree/9X5AQWln">r-trees</a>.
</p><p>In database management systems, a reverse key index strategy reverses the <a href="/facts/Unique_key/NKGBxUHR">key</a> value before entering it in the <a href="/facts/Index_(database)/TRqmk9It">index</a>. E.g., the value 24538 becomes 83542 in the index. Reversing the key value is particularly useful for indexing data such as <a href="/facts/Surrogate_key/rJu9oHHX">sequence numbers</a>, where each new key value is greater than the prior value, i.e., values monotonically increase. Reverse key indexes have become particularly important in high volume <a href="/facts/Transaction_processing_system/FxEUdWIt">transaction processing systems</a> because they reduce <a href="/facts/Block_contention/6MblgufE">contention</a> for index <a href="/facts/Block_(data_storage)/S3vT7c6N">blocks</a>.
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Reverse index open-in-new

Reverse index