incubator-couchdb-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Mario Scheliga <ma...@sourcegarden.de>
Subject Re: Chaining of views/MapReduce
Date Wed, 17 Feb 2010 23:23:06 GMT
but i thought, map-function only read data and create new ones (in the  
map only).
writing docs is left to the other processes (put docs or update)


Am 17.02.2010 um 23:29 schrieb Norman Rosner:

>
> On 17.02.2010, at 23:15, Mario Scheliga wrote:
>
>> Hi Norman,
>>
>> updating a document from map-function its not possible and seems to  
>> be the wrong way.
>> Thinking of map function processing docs seperatly (sandbox), so  
>> you are able to
>> spread the execution over thousand of servers ;-)
>
> True that! But: suppose I'm just creating/updating one document per  
> couchdb-instance, that should be ok, right? Because after that, I  
> can easily get all the result documents and merge them together. I  
> would do it in as similar way in Hadoop. And as far as I read in the  
> loooong archives of this list, I'm not the only one who wants to do  
> such things.
>
> cheers,
> norman
>
>>
>> greez
>> mario
>>
>> Am 17.02.2010 um 21:04 schrieb Norman Rosner:
>>
>>> Hi folks,
>>>
>>> first, I'll have to admit that I'm kinda new to JavaScript and of  
>>> course to CouchDB.  Second I just reuse the subject so I hope it  
>>> also pops up if anybody searches for it.
>>>
>>> As I read chaining of views is not possible yet but it's mentioned  
>>> couple of times on the mailing list. So here's what I want to do:
>>>
>>> 1. Create a list of unique labels/tags/whatever through all of the  
>>> documents (e.g. all nouns that are in the documents)
>>> 2. Extract all labels/tags/nouns of each document and check them  
>>> again the before calculated result in some kind of way
>>>
>>> For the second point I created a view which works except of the  
>>> checking against the result from point 1. Now I'm trying to solve  
>>> point 1.
>>> And here my questions begin: How can I create/update a document  
>>> from inside of a map function? As I think of it, I'll have to make  
>>> a HTTP GET to load the document in each iteration. I found some  
>>> HTTP stuff in the test.js in the test folder, but I'm not quite  
>>> sure how to use it and if it's the right way of thinking? Is there  
>>> any way of using global variables throughout 'couchapps' (e.g.  
>>> through the lib folder and thelike)?
>>>
>>> Any help of you CouchDB kings would be greatly appreciated!
>>>
>>> Cheers,
>>>
>>> norman
>>
>>
>> --
>> Sourcegarden GmbH HR: B-104357
>> Steuernummer: 37/167/21214 USt-ID: DE814784953
>> Geschaeftsfuehrer: Mario Scheliga, Rene Otto
>> Bank: Deutsche Bank, BLZ: 10070024, KTO: 0810929
>> Schoenhauser Allee 51, 10437 Berlin
>>
>


--
Sourcegarden GmbH HR: B-104357
Steuernummer: 37/167/21214 USt-ID: DE814784953
Geschaeftsfuehrer: Mario Scheliga, Rene Otto
Bank: Deutsche Bank, BLZ: 10070024, KTO: 0810929
Schoenhauser Allee 51, 10437 Berlin


Mime
View raw message