# tracking binary files

2 messages from 2009-02-19 to 2009-02-19. Participants: bill lam, Jeff King.
Thread: https://gitlist.dev/t/17883

## bill lam, 2009-02-19 03:16

Subject: tracking binary files
Message-ID: <20090219031602.GD20416@b2j>
URL: https://gitlist.dev/e/20090219031602.GD20416%40b2j

```
I would like to use git to track some database files of sizes from 1MB
to 50MB.  I want to know does git compress them for storage or not.
If so, what will be the expected compression ratio.  Those files
normally compressed to 25% of original size using zip.

-- 
regards,
====================================================
GPG key 1024D/4434BAB3 2008-08-24
gpg --keyserver subkeys.pgp.net --recv-keys 4434BAB3
唐詩312 王維  渭城曲
    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

```

## Jeff King, 2009-02-19 03:52

Subject: Re: tracking binary files
Message-ID: <20090219035219.GB19862@coredump.intra.peff.net>
URL: https://gitlist.dev/e/20090219035219.GB19862%40coredump.intra.peff.net
In-Reply-To: <20090219031602.GD20416@b2j>

```
On Thu, Feb 19, 2009 at 11:16:02AM +0800, bill lam wrote:

> I would like to use git to track some database files of sizes from 1MB
> to 50MB.  I want to know does git compress them for storage or not.

Yes, git will compress them via zlib.

> If so, what will be the expected compression ratio.  Those files
> normally compressed to 25% of original size using zip.

Then I would expect the same ratio, since I believe zip and zlib both
use the "deflate" algorithm.

Note, however, that git will also do delta compression between versions.
So storing N versions of a file should be no _worse_ than zipping and
keeping those N versions. But if the database files have small enough
changes from version to version (which depends on the database format,
and how much the on-disk structure changes for each update) then it will
compress even more.

-Peff

```