Binary delta compression

Binary delta compression (BDC) is a technology used in software deployment for distributing patches.

Erläuterung

Das Herunterladen großer Datenmengen über das Internet für Software-Updates können induzieren hohen Netzwerkverkehr Probleme, vor allem, wenn ein Netzwerk von Computern beteiligt ist. Binary Delta Compression, genannt "binäre Deltakompression" ermöglicht eine deutliche Verringerung der Download-Größe da nur der Unterschied zwischen em alten und dem neuen Dateien durchgeführt wird.

Implementation

In real world implementations, it is common to also use standard compression techniques (such as Lempel-Ziv) while compressing. This makes sense because LZW already works by referring back to re-used strings. ZDelta is a good example of this, as it is built from ZLib. The algorithm works by referring to common patterns not only in the file to be compressed, but also in a source file. The benefits of this are that even if there are few similarilties between the original and the new file, a good compression ratio is attained.

See also

• Delta encoding
• Remote Differential Compression

External links

• White paper for Microsoft's implementation of BDC technology