Some questions on large attachments

[Stefan Klein]

Hi List,

When I upload a large (100-300MB in my case) file and the document is 
changed while I am uploading the file the upload will fail because the 
revision had changed. So I thought of having separate documents for the 
files and move them to the destination document after the upload is 
complete.

Is it possible to copy (or move) an attachment from one document to an 
other without downloading and re uploading the file?
if it's possible, will it also work between 2 databases on the same 
instance?

If the same file is attached to 2 or more documents, will couchdb hold 
one copy for each or is it possible to tell couchdb these are the same, 
you only have to store it once?

thanks,
Stefan