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From: "ara.t.howard" <ara.t.howard@gmail.com>
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Subject: Re: Thinking outside the RDBMS box - how do I... ?
Date: Tue, 28 Oct 2008 10:42:47 -0600
References: <9a60b7b50810280834m3f0c662u139f24bd439202ad@mail.gmail.com>
 <e282921e0810280917q166a6271u29d2575f6e38bacd@mail.gmail.com>


On Oct 28, 2008, at 10:17 AM, Chris Anderson wrote:

> When a message comes from a phone, create a document like so:
>
> {
> "_id":"0b3a963dc37079652fa3092223be35b5",
> "_rev":"1805961941",
> "message" : "hey all this is the message",
> "phone": "971 555-1212",
> "time": "2008/06/30 06:30:35 +0000"
> }
>
> this document would never need to be updated, except in the case of  
> deletion.
>
> Also maintain docs for groups, eg:
>
> {
> "_id":"0b3a963dc37079652fa3092223be35b5",
> "_rev":"1805961941",
> "group" : "a group can have a title",
> "phones": ["971 555-1212","818 555-1212", "503 555-1212", "512  
> 555-1212"],
> }
>
> Then to load all the messages from phones in a group, GET the group
> document, then run a multi-key request against a map view of the
> messages, which is keyed by phone number. You have the whole thing in
> 2 requests.

the issue i see with that, and with any approach that requires a mutli  
document design with couch, is how to perform multi doc updates.  take  
the above and imagine someone changes their phone number, getting all  
the messages and updating them, along with any group documents, is  
very error prone as it consumes a ton of read/write pairs during which  
any failure of the system could leave the db in an inconsistent  
state.  this applies to the more mundane task of just making a tweak  
to the data too - like say we realized our code was appending 1+ for  
domestic numbers and shouldn't have been....  i guess the more general  
issue is that, with couch, keep denormalized data like this (the phone  
number) is problematic since there is not way to update it with acid  
properties.

having said that this does seem like a great application for couch.

a @ http://codeforpeople.com/
--
we can deny everything, except that we have the possibility of being  
better. simply reflect on that.
h.h. the 14th dalai lama