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From Paul Davis <>
Subject Re: rev of aggregate results
Date Fri, 03 Apr 2009 20:13:40 GMT
On Fri, Apr 3, 2009 at 4:04 PM, Adam Wolff <> wrote:
> Oh, I'm not concerned that I'm not seeing the most recent info -- just
> wondering what's the fastest way to find out if the application has
> the most recent data.
> Tell me more about "view tags." That may be exactly what I'm looking
> for. Is that an ETAG for the view results?

Exactly. I should've been more specific. Also, it looks like etags are
already in.

> A
> On Fri, Apr 3, 2009 at 11:59 AM, Paul Davis <> wrote:
>> Maybe I'm missing something, but assuming you're not using the
>> stale=ok flag you should be guaranteed that the view you're seeing is
>> the most recently completed update after your request was received.
>> Ie, it'll wait if the view is being updated.
>> If view tags are in trunk that'd capture the information on the state
>> of the btree. I'm not sure if that patch has made it in yet though.
>> Or I could be way off base with what you're asking.
>> HTH,
>> Paul Davis
>> On Fri, Apr 3, 2009 at 2:32 PM, Adam Wolff <> wrote:
>>> Hi,
>>> I've noticed a pattern that appears in a couple of places in our app.
>>> We have views which return multiple documents for a given key. What's
>>> the fastest way that we can determine if we have the current rev of
>>> the view, if we define a view's rev as the id and revs of all the
>>> documents in the view?
>>> The solution I've thought of so far is to write the view's map
>>> function like this:
>>> map : function(doc){
>>>   var key = computeKey(doc);
>>>   emit([key,, doc.rev], null);
>>> }
>>> We query the view with startkey=[key, null, null]&endkey=[key, {}, {}]
>>> and the rev for that key is just the text of the response. We haven't
>>> gotten all the way through this, but it sees like it should work. My
>>> concern is that this string will get unwieldy when there are a lot of
>>> docs in the result set.
>>> Is there a recipe for determining the rev of a document collection?
>>> Something in the semantics of id or rev that I've missed?
>>> Thanks in advance,
>>> Adam

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