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From "Paul Davis" <>
Subject Re: Architectural advice requested, and some 1.0 suggestions.
Date Thu, 06 Nov 2008 05:06:21 GMT
On Thu, Nov 6, 2008 at 12:03 AM, Antony Blakey <> wrote:
> On 06/11/2008, at 3:15 PM, Paul Davis wrote:
>> When we index outside of erlang, we don't have the consistent
>> read-state guarantee if we page through the _all_docs_by_seq view as
>> per usual design pattern. We could read the entire thing view into
>> memory, but that has the obvious not-scalable side effect. Thus by
>> default all external indexers (external == accessing couchdb via http)
>> would have the second form of updating until they reach a steady
>> state. This in deed could lead to race conditions with an indexer
>> never managing to stay quite in sync.
> Yet another reason to write a plugin rather than a loosely coupled
> _external, and use a core equivalent to an _all_docs_by_seq iterator that
> gives a consistent snapshot.

Not everyone is willing to pick up erlang just for the ability to play
with couch in their own particular domain. Also, it allows for
bridging the gap between disparate systems fairly easily.

>> As for the specifics of mnesia vs. sqlite I couldn't tell you. My
>> guess is that the mnesia integration would kick the crap out of the
>> sqlite integeration seeing as mnesia is part of the core library. But
>> you mentioned GIS stuff and I haven't a clue on mnesia support for
>> such things. Also, mnesia has that whole horizontal scale thing baked
>> in.
> I'm not interested in GIS, I just used GeoCouch as an example of an external
> indexer. I think Mnesia will do what I want for indexing.
> Thanks,
> Antony Blakey
> -------------
> CTO, Linkuistics Pty Ltd
> Ph: 0438 840 787
> The fact that an opinion has been widely held is no evidence whatever that
> it is not utterly absurd.
>  -- Bertrand Russell

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