W3C home > Mailing lists > Public > public-lod@w3.org > September 2012

Re: Expensive links in Linked Data

From: Kingsley Idehen <kidehen@openlinksw.com>
Date: Fri, 28 Sep 2012 12:45:25 -0400
Message-ID: <5065D425.7080906@openlinksw.com>
To: public-lod@w3.org
On 9/28/12 11:12 AM, Giovanni Tummarello wrote:
> Short answer is no,
>
> "linked data standards" have never addressed this and many other even
> basic problems(e.g. what if there are too many properties of one kind,
>   what kind of level of description you're supposed to get (e.g.
> recourse on blank nodes?), what is a standard way to find the entry
> URI for an object exposed given a description?  etc etc.
>
> Just create a normal web API (rest?)  and throttle/meter/bill as
> desired using one of the services to do that quickly
> my2c
> Gio

Is this for Linked Data standards or Linked Data platforms to solve?

A Linked Data platform can provide a scrollable cursor of the data, net 
effect you have a sliding window over the data. Of course, you can have 
a sliding window to hell if the data is so large that computation can't 
complete in say 250 msec. Thus, you need the ability to build cursors 
from partial computations.

To cut a long story short, that's a feature of the Virtuoso DBMS hosted 
faceted browser engine. That's what it can perform faceted browsing at 
massive scales on live Web services (29 Billion, 50 Billion, etc..).

This is a good old DBMS platform challenge! The 50 Billion+ LOD Cloud 
Cache instance will demonstrate what I've outlined above, ETA for going 
live is sometime in the next 5-7 days.

Francois: thanks for the question, it exposes a vital problem that's 
vital to practical Linked Data exploitation across intranets, extranets, 
and the public web.

Link:

1. 
http://virtuoso.openlinksw.com/dataspace/dav/wiki/Main/VOSScalableInference
2. http://docs.openlinksw.com/virtuoso/anytimequeries.html -- how to use 
timeouts to control cursor sizes re. partial results handling
3. 
http://virtuoso.openlinksw.com/dataspace/dav/wiki/Main/VirtuosoFacetsWebService 
.

Kingsley
>
> On Fri, Sep 28, 2012 at 4:54 PM, SERVANT Francois-Paul
> <francois-paul.servant@renault.com> wrote:
>> Thanks,
>>
>> no, this doesn't solve the problem. A user gets ex:e0 (the "cheap" resource). Though she can see that there is the link to the "expensive resource", she doesn't know the meaning of the link (it is just an owl:sameAs): she doesn't know what this is about. (Note also that there could be several expensive properties)
>>
>> Best,
>>
>> fps
>>
>>
>>
>>> -----Message d'origine-----
>>> De : Heiko Paulheim [mailto:paulheim@ke.tu-darmstadt.de]
>>> Envoyé : vendredi 28 septembre 2012 16:42
>>> À : public-lod@w3.org; SERVANT Francois-Paul
>>> Objet : Re: Expensive links in Linked Data
>>>
>>> Hi Francois-Paul,
>>>
>>> how about that solution:
>>>
>>> You publish the "cheap" data about your entity under
>>> http://example.org/e0, which is the "official" URI of that entity:
>>> ex:e0 owl:sameAs ex:e0expensive
>>> ex:e0 :cheapProp ...
>>>
>>> And under http://example.org/ex:e0expensive, you publish
>>> ex:e0expensive owl:sameAs ex:e0 ex:e0expensive :expensiveProp ...
>>>
>>> So people following links in LOD will always land at a page
>>> without the expensive properties, and those who really want
>>> to know can follow the sameAs link.
>>>
>>> Does that solve your problem?
>>>
>>> Best,
>>> Heiko
>>>
>>>
>>>
>>> Am 28.09.2012 16:32, schrieb SERVANT Francois-Paul:
>>>> Hi,
>>>>
>>>> How do you include links to results of computations in Linked Data?
>>>>
>>>> For instance, you publish data about entities of a given
>>> class. A property, let's call it :expensiveProp, has this
>>> class as domain, and you know that computing or publishing
>>> the corresponding triples is expensive. In such a case, you
>>> don't want to produce these triples each time one of your
>>> entities is accessed. You want to include in the
>>> representation of your entity only a link to that information.
>>>> A no-brainer, at first sight.
>>>>
>>>> Are there any recommended ways to proceed?
>>>>
>>>> TIA
>>>>
>>>> fps
>>>> -- Disclaimer ------------------------------------
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>>> --
>>> Dr. Heiko Paulheim
>>> Knowledge Engineering Group
>>> Technische Universität Darmstadt
>>> Phone: +49 6151 16 6634
>>> Fax:   +49 6151 16 5482
>>> http://www.ke.tu-darmstadt.de/staff/heiko-paulheim
>>>
>>>
>> -- Disclaimer ------------------------------------
>> Ce message ainsi que les eventuelles pieces jointes constituent une correspondance privee et confidentielle a l'attention exclusive du destinataire designe ci-dessus. Si vous n'etes pas le destinataire du present message ou une personne susceptible de pouvoir le lui delivrer, il vous est signifie que toute divulgation, distribution ou copie de cette transmission est strictement interdite. Si vous avez recu ce message par erreur, nous vous remercions d'en informer l'expediteur par telephone ou de lui retourner le present message, puis d'effacer immediatement ce message de votre systeme.
>>
>> *** This e-mail and any attachments is a confidential correspondence intended only for use of the individual or entity named above. If you are not the intended recipient or the agent responsible for delivering the message to the intended recipient, you are hereby notified that any disclosure, distribution or copying of this communication is strictly prohibited. If you have received this communication in error, please notify the sender by phone or by replying this message, and then delete this message from your system.
>>
>>
>


-- 

Regards,

Kingsley Idehen	
Founder & CEO
OpenLink Software
Company Web: http://www.openlinksw.com
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Received on Friday, 28 September 2012 16:45:52 UTC

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