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Reply-To: user@couchdb.apache.org
Date: Tue, 27 Jun 2017 01:42:13 -0400 (EDT)
From: Joan Touzet <wohali@apache.org>
Reply-To: Joan Touzet <wohali@apache.org>
To: Vladimir Kuznetsov <vovanec@gmail.com>
Cc: user@couchdb.apache.org
Message-ID: <108567400.1449.1498542131968.JavaMail.Joan@RITA>
In-Reply-To: <71E5C0C4-27A8-4DED-BB53-8CA6CCAA4383@gmail.com>
References: <5B8E4FB0-A875-4F16-9FB7-8775DD95FA73@gmail.com> <1952339179.1395.1498537282310.JavaMail.Joan@RITA> <71E5C0C4-27A8-4DED-BB53-8CA6CCAA4383@gmail.com>
Subject: Re: _global_changes purpose
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Thread-Topic: _global_changes purpose
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archived-at: Tue, 27 Jun 2017 05:42:26 -0000

_db_updates is powered by the _global_changes database.

-Joan

----- Original Message -----
From: "Vladimir Kuznetsov" <vovanec@gmail.com>
To: user@couchdb.apache.org, "Joan Touzet" <wohali@apache.org>
Sent: Tuesday, 27 June, 2017 12:39:55 AM
Subject: Re: _global_changes purpose

Hi Joan

I heard /_db_updates is the feed-like thing I could subscribe to listen to the global updates(same way you described). It is not very clear why would I need access to _global_changes database when I already have /_db_updates method with pagination and long-polling features.

Is listening on _global_changes's /_changes feed the same as listening on /_db_updates? Or is there any difference? What is preferred?

thanks,
--Vovan


> On Jun 26, 2017, at 9:21 PM, Joan Touzet <wohali@apache.org> wrote:
> 
> Say you have 100 databases and you want to know when something changes on all
> of them. In 1.x you have to open 100 _changes continuous feeds to get that
> information. In 2.x you have to open a single connection to _global_changes.
> 
> Think of the possibilities.
> 
> -Joan
> 
> ----- Original Message -----
> From: "Vladimir Kuznetsov" <vovanec@gmail.com>
> To: user@couchdb.apache.org
> Sent: Monday, 26 June, 2017 8:47:46 PM
> Subject: _global_changes purpose
> 
> Hi guys
> 
> I cannot find any good explanation what's the purpose of _global_changes system database in CouchDB 2.0. Can somebody please explain or provide some pointer?
> 
> thanks
> --Vovan