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From Ryan Hiebert <r...@ryanhiebert.com>
Subject Re: replication order
Date Thu, 19 May 2011 18:43:25 GMT
The main thing I was worried about is that the changes would be applied in replication in the
order that I made them (assuming I made the changes from one node).  In our case, we associate
IP address documents that contain DNS host information.  We'd like to make sure that a dns
hostname is only ever associated with the correct IP address, so that when I move the dns
hostname from from one IP address document to another, I can be sure that if it shows up in
the new document, it is NOT in the old one.

I know that perhaps a more preferred way of making sure non-duplicity would be to make dns
documents instead, but that constraint is not universal.  Sometimes I do want multiple IP
addresses for a domain.  Just sometimes I don't, and I want to make sure that change can be
counted on happening the way that I've done it.

On May 18, 2011, at 6:28 PM, Sean Copenhaver wrote:

> I'm curious why are you worried about multiple revisions of a document?
> 
> 
> 
> On May 18, 2011, at 7:20 PM, Paul Davis <paul.joseph.davis@gmail.com> wrote:
> 
>> On Wed, May 18, 2011 at 7:08 PM, Ryan Hiebert <ryan@ryanhiebert.com> wrote:
>>> When replication is being done, in what order will the changes be applied?  In
the order that they happened, or in the order of the _id they refer to, or some other ordering,
or is there no ordering that can be expected.  For instance, if I move a document, I would
like to make sure that I never have two versions of the document.  To this end, I first delete
the document, and then create it again with the new _id.  In a replicated database, can I
be sure that the document will be first deleted, and then created on the replicated database?
>>> 
>>> Thanks,
>>> 
>>> Ryan
>> 
>> The updates are applied in the order of the update sequence. You can
>> view that sequence using the changes feed. Your proposed scenario is
>> listed under "assuming those are the only two edits applied to those
>> two docs in any database that ever replicates with your network of
>> dbs, then yes".


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