Re: [caldav] new webdav sync draft

Helge Hess <helge.hess@opengroupware.org> Sun, 06 December 2009 21:34 UTC

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From: Helge Hess <helge.hess@opengroupware.org>
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Date: Sun, 06 Dec 2009 22:34:33 +0100
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To: Arnaud Quillaud <Arnaud.Quillaud@Sun.COM>
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Subject: Re: [caldav] new webdav sync draft
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Hi,

Arnaud asked me on my opinion on the following ...

On 19.11.2009, at 18:20, Arnaud Quillaud wrote:
> I have just submitted a new version of the webdav sync draft (http://www.ietf.org/id/draft-daboo-webdav-sync-02.txt ).

=>
>    2.  Do clients really need to be notified that a resource was created
>        versus modified ?  They should be able to figure that out by
>        looking at the state of their current cache.  If this information
>        is not necessary, the response would not need to contain a DAV:
>        status along with the DAV:propstat.  This would allow the use of
>        a regular multistatus (simply extended with a sync-token
>        element).

Its not crucial, but helpful. If I don't know that a resource is new, I obviously have to scan the cache to check for that. Which is significantly more expensive than a simple INSERT (status = 'N', url=abc) ...
Given that WebDAV sync is supposed to improve sync with large folders, the 'check' time consumption becomes more relevant too ...

The question is whether I would do the scan anyways, just to be sure there are no DUPs. Probably! :-) [either me, or a database unique constraint doing effectively the same thing]

So I guess either way is fine with me with a slight preference towards having a separate 'created'. If that would be significantly more difficult for servers, lets drop it, if not, lets preserve it.

Greets,
  Helge