Delta compression

From Biocrawler, the free encyclopedia.

In software configuration management (SCM), a "delta" is a type of file in which the difference (or diff) between two successive versions, is recorded. This term suggests that differences should be small (2% different in average). So, using it can vastly reduce the amount of storage required.

A delta can be defined in 2 ways,symmetric delta and directed delta.

A symmetric delta can be expressed as , where v₁ and v₂ represent two successive versions.

A directed delta, also called a change, is a sequence of (elementary) change operations which, when applied to one version v₁, yields another version v₂. (note the correspondence to transaction logs in datbases).

See also

• Delta encoding

Wikipedia (http://en.wikipedia.org/wiki/Main_Page) Delta_compression (http://en.wikipedia.org/wiki/Delta_compression) version history (http://en.wikipedia.org/w/index.php?title=Delta_compression&action=history) GNU Free Documentation Lizenz (http://en.wikipedia.org/wiki/Wikipedia:Text_of_the_GNU_Free_Documentation_License) CC-by-sa (http://creativecommons.org/licenses/by-sa/2.5/)

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