I am interested about how SharePoint 2010 saves.
Does it do incremental / transactional saves? In other words, when you edit a document, does it save a whole new document, or does it only actually save the edited portions?
This to me is very important and could sway whether or not I get it.
I think this thread might answer your questions - http://social.msdn.microsoft.com/Forums/en/sharepoint2010general/thread/ba05c31e-8431-4f65-861d-574182f17930
In summary, document versioning in SharePoint 2010 does not seem to be changed in that the entire binary representation of the files are stored for each version. However, they have improved large file support via numerous new ways of outsourcing storage of the document.
If you are after delta revisions for your Office docs (e.g. to minimise storage) then you might find that older office document types (.doc, .xls, etc) will never support deltas because they were a binary format. The newer ones (.docx, .xlsx, etc) may be supported since they are simply multiple XML inside a zip file. However, I'm not aware of any systems that support the auto-unzip then delta functionality (plus apply-delta then re-zip) functionality that I think you're asking for. This thread on the topic is interesting - Will Subversion efficiently store OpenXML Office documents?.
I Don't know for sure. So what I say is just what I imagine.
But I Think it saves the complete document, specially when the library is on version control and it needs to have different versions.
I am sure curious to know why does that matter to you using it.
