openoffice - .odt vs .fodt: which is most space effective for git repositories?

Which is most space effective for git repositories: LibreOffice/OpenOffice .odt files or .fodt files? I think that it should be .fodt, since with the uncompressed XML format .fodt the repository compressor will be able to effectively use redundancies between files, whereas the .odt files are already compressed and can't be compressed further. But that's just a guess. Does anyone have any practical experience?

Answer

I performed following test:

Put 5 revision of small .odt to repository. I made small changes in every odt-document.

I commit similar data for .FODT. They are obtained by extracting corresponding revision of ODT and saving it to .FODT.

My results follow:

       before gc    after gc      
odt      260k         260k                
fodt     118k         38k        

Note, I measured size of .git directory where revision actually saved.

I did not accounted ODT/FODT-file itself because this does not give reasonable results.

I measured size of .git folder only.

ODT is very similar to zipped FODT and it is expected that FODT is much larger than ODT.

Since it may sense to estimate grows of Git history then ODT/FODT should be excluded when measuring size of Git, because they are stored directly one time only independently of history length. In long run history consumes most space, so to obtain more relevant measurements on simple test the documents itself in working directory should be NOT be accounted when estimating the size of repo.