{"thread":{"id":"17883","subject":"tracking binary files","startedAt":"2009-02-19T03:16:02Z","lastAt":"2009-02-19T03:52:19Z","messageCount":2,"participants":["bill lam","Jeff King"],"isPatch":false,"patchVersion":null,"patchTotal":null},"messages":[{"id":"105376","messageId":"20090219031602.GD20416@b2j","threadId":"17883","inReplyTo":null,"subject":"tracking binary files","fromName":"bill lam","fromEmail":"cbill.lam@gmail.com","sentAt":"2009-02-19T03:16:02Z","receivedAt":"2009-02-19T03:16:02Z","isPatch":false,"sender":{"key":"cbill.lam@gmail.com","avatar":null},"body":"I would like to use git to track some database files of sizes from 1MB\nto 50MB.  I want to know does git compress them for storage or not.\nIf so, what will be the expected compression ratio.  Those files\nnormally compressed to 25% of original size using zip.\n\n-- \nregards,\n====================================================\nGPG key 1024D/4434BAB3 2008-08-24\ngpg --keyserver subkeys.pgp.net --recv-keys 4434BAB3\n唐詩312 王維  渭城曲\n    渭城朝雨浥輕塵  客舍青青柳色新  勸君更盡一杯酒  西出陽關無故人\n"},{"id":"105382","messageId":"20090219035219.GB19862@coredump.intra.peff.net","threadId":"17883","inReplyTo":"20090219031602.GD20416@b2j","subject":"Re: tracking binary files","fromName":"Jeff King","fromEmail":"peff@peff.net","sentAt":"2009-02-19T03:52:19Z","receivedAt":"2009-02-19T03:52:19Z","isPatch":false,"sender":{"key":"peff@peff.net","avatar":"https://avatars.githubusercontent.com/u/45925?v=4"},"body":"On Thu, Feb 19, 2009 at 11:16:02AM +0800, bill lam wrote:\n\n> I would like to use git to track some database files of sizes from 1MB\n> to 50MB.  I want to know does git compress them for storage or not.\n\nYes, git will compress them via zlib.\n\n> If so, what will be the expected compression ratio.  Those files\n> normally compressed to 25% of original size using zip.\n\nThen I would expect the same ratio, since I believe zip and zlib both\nuse the \"deflate\" algorithm.\n\nNote, however, that git will also do delta compression between versions.\nSo storing N versions of a file should be no _worse_ than zipping and\nkeeping those N versions. But if the database files have small enough\nchanges from version to version (which depends on the database format,\nand how much the on-disk structure changes for each update) then it will\ncompress even more.\n\n-Peff\n"}]}