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Date: Wed, 11 Feb 2009 13:49:10 -0500
Message-ID: <e2111bbb0902111049w343ed548n3e47b0ff92c266f3@mail.gmail.com>
Subject: Re: [user] Thoughts on document/views...
From: Paul Davis <paul.joseph.davis@gmail.com>
To: user@couchdb.apache.org
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On Wed, Feb 11, 2009 at 1:28 PM, Wout Mertens <wmertens@cisco.com> wrote:
> On Feb 11, 2009, at 7:22 PM, kowsik wrote:
>
>> Just something that occurred to me and wanted to run it by you guys.
>> For pcapr, I have a number of different types of documents in
>> couch-db, some are comments, some are about the packets, etc. Now, I
>> have views that do something like this:
>>
>> map: function(doc) {
>>   if (doc.type == 'comment') emit(...);
>> }
>>
>> With a large set of documents and a large set of views, any new
>> document or updates to document is passed to __all__ of the views
>> (when the view is eventually invoked). But I "know" that my documents
>> come in classes and that only certain views really apply to them. I'm
>> thinking of a view as a static method on a class that gets some
>> information about the instances.
>>
>> What I'm getting at is, does it make sense to have some type of
>> document "class" attribute and then have views bound to these classes?
>> The goal, of course, being that couch-db can pre-filter a lot of these
>> things and only run the views for the appropriate types of documents.
>
> I'm probably speaking before my turn being such a newbie, but why wouldn't
> you create a new database for disjoint classes of documents?
>
> Also, once a view is run on a document, it doesn't get re-run that often
> does it?
>
> So other than eating diskspace, maybe there's not really anything wrong with
> keeping everything in one db.
>
> Wout.
>
>

There's nothing at all wrong with keeping lots of multiple document
types in a single database. 1 db != 1 table etc etc.

When a view is rerun it is only executed once for each document that
changed. It doesn't matter how many times the document changed either.

HTH,
Paul Davis