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Re: SPARQL-friendly alternative to rdf:Lists?

From: David Booth <david@dbooth.org>
Date: Mon, 14 Oct 2013 13:23:40 -0400
Message-ID: <525C289C.7020306@dbooth.org>
To: Antoine Zimmermann <antoine.zimmermann@emse.fr>, semantic-web@w3.org
Interesting trick!  I wouldn't want to use it in practice (for 
performance reasons), but it is quite a creative use of SPARQL.  Thanks 
for pointing it out.

David

On 10/14/2013 11:00 AM, Antoine Zimmermann wrote:
> I suggest that you look at this answer by Joshua Taylor in Stackoverflow:
>
> stackoverflow.com/questions/17523804/is-it-possible-to-get-the-position-of-an-element-in-an-rdf-collection-in-sparql/17530689#17530689
>
>
>
> It shows a pure SPARQL 1.1 query that returns all the elements of a list
> ordered by their position in the list. Very nice trick.
> However, it also shows that using this trick will blow up the execution
> time when the number of elements increase, and a customised programmatic
> solution is far more efficient in general.
>
>
>
> AZ.
>
>
>
>
>
> Le 11/10/2013 16:02, David Booth a écrit :
>> rdf:Lists are notoriously difficult to use in SPARQL if one wishes to
>> retain the *order* of the items in the list.  James Leigh and David Wood
>> made a nice proposal a few years ago to address this problem directly at
>> the RDF level,
>> http://www.w3.org/2009/12/rdf-ws/papers/ws14
>> but for whatever reasons, that work was not included in the charter of
>> the current RDF working group.  As a result people often use some other
>> means of representing ordered lists in RDF, such as by [item, index]
>> pairs.
>>
>> For those who use an alternate way to represent an *ordered* list of
>> items in RDF (instead of rdf:List), I am wondering:
>>
>> 1. What *ordered* list representation do you prefer, and why?
>>
>> 2. Have there been any efforts toward standardizing alternative
>> *ordered* list representations in RDF?  E.g., has anyone written up a
>> spec on how they prefer to do it?
>>
>> Thanks,
>> David
>>
>>
>
Received on Monday, 14 October 2013 17:24:08 UTC

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