Will Subversion efficiently store OpenXML Office documents?

Question

Hello,

I have been managing Subversion as an engineering document storage repository for my company. It is working fairly well, however I have a question about how MS Office 2007 formats are (should be) handled by Subversion.

I'm looking at an Excel 2007 spreadsheet (extension .xlsx) in my working copy that Subversion has applied the svn:mime-type property application/octet-stream. This means that Subversion is treated it as binary, right?

I was hoping that the new MS Office document formats would be stored efficiently by Subversion. My understanding is that a full copy of a binary file will be made on every commit of that file, whereas if the file is text, a small change to the file will result in a small amount of additional data being added to the repository (in a typical situation at least).

I don't understand much of the details of XML, but I thought that an XML file was text, and that it would therefore be efficiently stored by Subversion.

Is it possible to configure Subversion so that MS Office OpenXML documents are stored efficiently?

Follow-up (2009-11-09): I've found that Office documents can be stored as plain text using the Office 2003 XML document formats (Excel: XML Spreadsheet 2003; Word: Word XML Document. There is a warning about loss of formatting, but I have yet to encounter any noticeable loss of formatting.

Answer 1

Have you ever tried to open an OpenXML file in a text editor?

To make it short: it is not text, it is still binary. So no, you can’t make Subversion handle it any different.

Answer 2

Sadly, you can't currently do this with Subversion, but there has been some discussion around this:

http://subversion.tigris.org/ds/viewMessage.do?dsForumId=462&dsMessageId=651443

Answer 3

Subversion handles binary files quite well. It does not store a full copy for every commit but only an efficient binary diff.

See the FAQ about this.