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Subject: Re: Using _rev in application logic
From: Alan Boyce <alan@alanboyce.com>
To: user@couchdb.apache.org
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Date: Thu, 01 Apr 2010 09:59:38 -0400
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Hi Moritz

I wouldn't use _rev, see Jan's response. I would use update handlers.
See here:

http://wiki.apache.org/couchdb/How_to_intercept_document_updates_and_perform_additional_server-side_processing

So you could create a revision in the document on update.

{
title: "I'm a document",
body: "This couchdb stuff is cool."
revisions: [{title: "I'm a document", body:"this couchdb stuff is
cool."}],
update_note: "fixed capitalization of 'this' in body"
}

best,
alan


On Thu, 2010-04-01 at 14:32 +0200, Moritz Post wrote:
> Hi CouchDB people
> 
> I am currently playing with the couchdb and pretty impressed by several of
> the feature on offer. Great job so far. While reading up on various web
> resources i have come to conclude that it is discouraged to use the _rev
> field for application related logic since the revisions are removed when
> compacting and they are not replicated when using replication.
> 
> Looking at my possible usecase however, i would very much like to use the
> _rev key to track changes in my document. So here are several questions
> regarding that topic:
> 
> 1. Is it generally discouraged to use the _rev in application logic?
> 2. Is compacting something i would like to do for other reasons than to
> remove older revisions (so i could basically not do it)
> 2. Is it possible to somehow also replicate the revision while replicating?
> 3. Is it good practice to use the _rev field in views?
> 
> Any other clarifications in regards to _rev are also welcome.
> 
> Thanks in advance and keep up the good work
> 
> Greets
> Moritz