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From Sean Clark Hess <seanh...@gmail.com>
Subject Re: View Troubles
Date Tue, 02 Mar 2010 19:20:28 GMT
>
> No, although you can have a different view emitting [user, time, station]

instead of [user, station, time]


Good point. I'm constantly worried about size, since that database is 12 GB
without any views.

Multi-range queries have been mooted as a future feature.


Mooted? As in "decided to be moot"? I've never heard it used as a verb
before :) I'm ok working around it, but I don't really see why not to add it
if you're allowed to ask for multiple keys.

Do remember that views themselves can be compacted.


Woah, what? What does that even mean? I thought compaction just removed old
versions of documents. Does Couch keep around old versions of views?

Thanks for the tip about the caching.

On Mon, Mar 1, 2010 at 11:36 AM, Brian Candler <B.Candler@pobox.com> wrote:

> On Mon, Mar 01, 2010 at 10:16:11AM -0700, Sean Clark Hess wrote:
> > I think I'll just emit every half hour. I can't do ranges easily, because
> > another query needs to ask for "everything playing on all of a user's
> > stations at 10:00". I have to use the "keys" post for that, which doesn't
> > take ranges.
>
> No, although you can have a different view emitting [user, time, station]
> instead of [user, station, time]
>
> Multi-range queries have been mooted as a future feature.
>
> > Right now we're emitting the data we need for that (above) query as the
> > value for that view. I was mostly worried about size because we're
> emitting
> > so much data. Would it be much slower to emit null and use include_docs?
> > That would save a significant amount of disk space, right?
>
> The view index will be smaller by the size of each document. When fetching
> docs using include_docs=true it'll need to traverse the Btree to find them;
> but equally it will need to traverse less disk space for the view itself,
> and hence may find more of it in cache.  You'll need to evaluate the
> tradeoff yourself, but if you're only fetching some dozens of rows at a
> time
> I'd have thought the include_docs overhead would not be noticed.
>
> Do remember that views themselves can be compacted.
>
> Cheers,
>
> Brian.
>

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