Binary delta compression

<h2 id="explanation">Explanation</h2>
<p>Downloading large amounts of data over the Internet for software updates can induce high network traffic problems, especially when a network of computers is involved. <i>Binary Delta Compression</i> technology allows a major reduction of download size by only transferring the difference between the old and the new files during the update process.
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<h2 id="implementation">Implementation</h2>
<p>In real-world implementations, it is common to also use standard compression techniques (such as <a href="/facts/LZW/hJfgYm9j">Lempel-Ziv</a>) while compressing. This makes sense because LZW already works by referring back to re-used strings. <a href="https://web.archive.org/web/20060426221704/http://cis.poly.edu/zdelta/">ZDelta</a> is a good example of this, as it is built from <a href="/facts/Zlib/rExIchaK">ZLib</a>. 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 similarities between the original and the new file, a good <a href="/facts/Data_compression_ratio/eDEWGzTv">data compression ratio</a> is attained.
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<h2 id="see-also">See also</h2>
<ul><li><a href="/facts/Delta_encoding/2NQlyAUc">Delta encoding</a></li>
<li><a href="/facts/Remote_Differential_Compression/s31sMuFu">Remote Differential Compression</a></li></ul>
<h2 id="external-links">External links</h2>
<ul><li><a href="https://web.archive.org/web/20040829073928/http://www.microsoft.com/downloads/details.aspx?FamilyID=4789196c-d60a-497c-ae89-101a3754bad6&DisplayLang=en">White paper for Microsoft's implementation of BDC technology</a></li>
<li><a href="https://www.chromium.org/developers/design-documents/software-updates-courgette/">Courgette, a compression algorithm designed at Google to reduce the size of Google Chrome updates</a></li></ul>

Binary delta compression open-in-new

Binary delta compression