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From Stanley Iriele <>
Subject Re: Control view query performance
Date Mon, 14 Jul 2014 04:54:26 GMT
firstly..Thanks for the,I answer appreciate that. I was in a hurry while
writing the past email

To be slightly clearer. I know that the _changes feed is generated from
 some bookkeeping mechanism internal to the database. When I said
"Calculated for a particular set of entries" I mean the actual javascript
view server that is evaluating your map function because the doc(s) have
been fed to it and it must response with the emitted results. I ..could
have phrased that better.

My questions revolve around how CouchDB utilizes the view server...and if
there is only one of them running at a given time on a box.The docs suggest
that CouchDB talks to a view server with a line bases protocol, but I don't
know there can be more than one view server executing map functions at a
time...and if that a configurable thing?

On Sun, Jul 13, 2014 at 9:33 PM, Jens Alfke <> wrote:

> I am no expert on the implementation of CouchDB, but I don’t believe your
> question makes sense in the form that you asked it. The changes feed isn’t
> related to views at all. Rather, there’s an underlying by-sequence index in
> the main database that’s scanned to generate that feed. And it doesn’t
> “calculate” docs; it just returns existing doc IDs and revision IDs.
> If that’s not what you were actually asking, you’ll need to rephrase your
> question more clearly.
> —Jens
> On Jul 13, 2014, at 8:49 PM, Stanley Iriele <> wrote:
> > any thoughts on this?...Its not a blocker..I'd just really like to know
> >
> >
> > On Thu, Jul 10, 2014 at 3:44 PM, Stanley Iriele <>
> > wrote:
> >
> >> When a doc needs to be calculated for a particular set of entries from
> the
> >> changes feed...are docs sent one at a time or in batches?... And is
> there
> >> just one view server doing all of the computation.
> >>
> >> there a way to configure or control any of the settings that
> >> would dictate the above? number of view servers.. Or batch size
> for
> >> docs.... Etc... And if not should there be?.. But I've been very curious
> >> about this for a while... I looked a few view server implementations..
> >> But...meh
> >>

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