Here is a conversation I had on the IRC channel #couchdb on this subject on november 24, 2008 (2 days ago). Hope this helps!
(04:01:26 PM) dsimard: I just wanted to know if an attachment changes, will the new revision contain just the "diff" with the old attachment or the complete attachment? (04:01:49 PM) jan____: complete attachment. diffs are the devil (04:03:08 PM) dsimard: damn... all fields of a document are stored as a full document? (04:03:18 PM) dsimard: I really thought that diffs were used (04:03:35 PM) jan____: no, no diffs. diffs are the devil (04:04:14 PM) dsimard: ok, could you elaborate on the evilness of diffs? (04:04:44 PM) dsimard: I just want to know more about it (04:05:04 PM) jan____: dsimard: you need to keep diffs around forever to construct the latest live doc. this totally conflicts with the couchdb storage model which uses full representations of each revision. (04:05:04 PM) dsimard: or if you have a good link about it (04:05:35 PM) jan____: http://incubator.apache.org/couchdb/docs/overview.html (04:05:36 PM) jan____: that one In my opinion, it would be a great addition to couchdb. But still, I can't wait to use it on my next project. On Wed, Nov 26, 2008 at 3:25 PM, Liam Staskawicz <[EMAIL PROTECTED]> wrote: > > On Nov 26, 2008, at 12:20 PM, Noah Slater wrote: > > On Wed, Nov 26, 2008 at 09:57:24AM -0800, Liam Staskawicz wrote: >> >>> When updating a document, is there any notion of submitting a partial >>> update? >>> It seems like being able to specify that only some subset of the fields >>> in a >>> document should be updated would offer some efficiency benefits. I guess >>> I >>> had in mind some scenario where CouchDB would create the updated record >>> by >>> merging the existing revision with the new info and saving the updated >>> revision, but I'm still new to CouchDB so I don't have a good sense of >>> whether >>> this tramples on any important concepts. >>> >> >> Nope, CouchDB does not support this at the moment. If you want to make an >> update >> you have to send the entire document each time. >> >> There is some discussion among CouchDB users and developers about the >> benefits >> of partial updates but it seems the real sticking point so far is deciding >> on >> the mechanism for enabling this. It seems the rough consensus at this >> point is >> that whatever method we use be something that is standardised, either >> through a >> standards body or de facto within the larger JSON community. >> > > Thanks for the response - and yeah, this is not a sticking point at the > moment but as systems start to ramp up this seems like a pretty good way to > make the back and forths much more efficient. Will be looking forward to > this being introduced at some point. > > Liam >
