I'm trying to understand why subversion isn't just storing diffs of some binary 
files.  It looks like it's taking up more space than it needs to.

At length the issue is described here: http://stackoverflow.com/q/6917505/277208

The more summarized version is...

I understand that subversion stores files differentially (compressed), even for 
binary files.  And subversion uses Xdelta to help with this.

I can do a standalone xdelta on my 50MB zip files:
xdelta3.0z.x86-64.exe -e -s v1_path\data.zip v2_path\data.zip v1v2_delta.file

and get a nicely small v1v2_delta.file which is about 3MB.

But when I check successive versions of the data.zip into a subversion 
repository (FSFS, version 1.6.11) I get two ~50MB files in db\revs\0

I appreciate minimizing disk usage isn't the only thing, e.g. performance may 
be more important.  Being able to configure this would be useful in my 
situation.

I've spent a long time trying to figure out what is going on and not got very 
far.  I guess this behaviour is probably deliberate - it would be really 
interesting to have an idea of different factors deciding subversion behaving 
in this way.

Thanks
Jon

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