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Re: Open world issue (opening vs closing days) and SPARQL CONSTRUCT

From: Gregory Williams <greg@evilfunhouse.com>
Date: Wed, 21 May 2008 12:06:53 -0400
Message-Id: <745AC374-541D-40AA-B1DD-A6204C5A0F23@evilfunhouse.com>
To: Semantic Web <semantic-web@w3.org>
On May 21, 2008, at 2:49 AM, Ivan Mikhailov wrote:

> (:Tuesday :Sunday) is a good approach for non-SPARQL data retrieval,
> say, for explicit graph traversal. Due to scalability reasons, SPARQL
> has no features to deal with collections. Hence all what one can do  
> with
> SPARQL and (:Tuesday :Sunday) is to retrieve the head of the  
> collection
> and access it from application, making negation logic inside the
> application. That's quite OK if the application is co-located with the
> data source, otherwise one had to query for sequence items in sequence
> via net with all related ping times.

Since there are at most seven items in the list in this example, it  
should be possible to construct a single SPARQL query using chained  
OPTIONAL blocks to get all the :closingDays values.

.greg



Received on Wednesday, 21 May 2008 16:07:36 GMT

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