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From Andrew Melo <andrew.m...@gmail.com>
Subject Re: About denormalization and keep consistent
Date Fri, 09 Apr 2010 20:04:59 GMT
On Fri, Apr 9, 2010 at 3:00 PM, Michael Ludwig <milu71@gmx.de> wrote:
> Andrew Melo schrieb am 09.04.2010 um 14:24:24 (-0500)
> [Re: About denormalization and keep consistent]:
>
>> On Fri, Apr 9, 2010 at 2:22 PM, faust 1111 <faust451@gmail.com> wrote:
>> >>Author changes their profile document.
>> >
>> >>Something listening to the _changes feed notices this.
>> >
>> >>It starts a process querying for docs that have the old author
>> >>profile, and fixing those docs. Eventually all the >docs have been
>> >>updated. Then its work is done.
>> >
>> > But how
>> >>Something listening to the _changes feed notices this.
>> > know about old author name?
>>
>> You have to tell it somehow. You can either ninja together some sort
>> of way to do it through couch or do something out-of-band to notify
>> your daemon process of what work it needs to do.
>
> Brave New World of NoSQL :-)
>
> Faust, if you care about data consistency to the extent it appears from
> this thread, you should model your data so that consistency is easy, and
> doesn't require ninjaing together some sort of way to unleash an armada
> of hackery-hoo against inconsistency, which thrives on redundancy and is
> a dreadful enemy if given rope, as in NoSQL land.
>
> I'm new here. Are there scenarios where writing happens to an SQL
> server, from where NoSQL replicas are fed and used to serve readers?

Possibly. But, if you're writing to a single SQL master, then you lose
two benefits of Couch: horizontally scalable writes and not having to
be restricted by SQL's data model. You could do (for instance) single
master writes and many-slave reads on a stock SQL server in that case.

best,
Andrew


> --
> Michael Ludwig
>



-- 
--
Andrew Melo

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