[DAIS-WG] RDF Specification Motivation Text

[Steven Lynden]

Hi,

This text has now been moved to the motivational document, now
available on Gridforge:

http://forge.gridforum.org/sf/go/doc15722

Note that this document is work in progress and is expected to undergo
a lot of changes over the coming weeks.

Regards,

Steven.

On Wed, Jul 15, 2009 at 1:40 PM, Mario Antonioletti<mario at epcc.ed.ac.uk> wrote:
>
> Hi,
>   Have had a look now and made some changes but I wanted you (and others) to
> see where I had made the changes so I put your text in word and did it with
> change tracking on. Have a look and let me know what you think.
>
> Couple of things:
>
> o who is the motivational document targetting? My call would be the
>  RDF community and not DAIS/Grid folks - right?
> o I think need to make more of the abstraction layer that is going
>  to be provided by the RDF ontology spec (and hopefully
>  implementation) ... there is still a battle to be had here as to
>  what constitutes access and management but can save that one til
>  later when Miguel finds that he has time.
>
> Let me know what you think ...
>
> Mario
>
> On Tue, 7 Jul 2009, Steven Lynden wrote:
>
>> Hi,
>>
>> At the last RDF telcon we decided that it was important to clearly
>> define the motivation for the RDF specifications. The text below is  a
>> potential addition to the motivational document to do this. Any
>> comments/additions welcome, especially about points that might not be
>> valid or things that have been missed.
>>
>> Regards,
>>
>> Steven.
>>
>> This document proposes extending the WS-DAI specifications, currently
>> including XML and relational realisations, to encompass RDF(S) data
>> resources. Standards for accessing databases from programming
>> languages (e.g. JDBC, XML:DB etc) have been widely used to save
>> programming effort and promote interoperability and the WS-DAI
>> specifications bring the same benefits to service-based computing. The
>> WS-DAI specifications provide a set of WSDL interfaces for managing,
>> querying and describing various properties associated with data
>> resources, an important aspect of this approach being that the
>> interfaces defined in the WS-DAI specifications can be seamlessly
>> combined with those defined by other web service standards that
>> concentrate on other areas, for example, security. Although the SPARQL
>> query language already has an associated W3C recommendation web
>> service-based protocol [SPARQL-Protocol] for executing SPARQL queries,
>> the RDF(S)-based WS-DAI specifications described in this document are
>> required for the following reasons:
>>
>> - The WS-DAI specifications set out standard patterns for querying,
>> managing and describing various aspects of data resources within the
>> context of service-based computing, for example operations exist for
>> configuring data resources and describing a data resource's ability to
>> support various features such as transactions. In contrast, the SPARQL
>> Protocol defines a single query operation and associated fault
>> messages but lacks the range of operations, properties and faults
>> defined within WS-DAI in order to fully support access to data
>> resources in a service-based setting. An RDF(S) realisation of WS-DAI
>> is therefore required to provide this support in an RDF(S) setting.
>>
>> - The SPARQL Protocol's SparqlQuery::query operation is analogous to
>> the direct data access query pattern specified by WS-DAI, where the
>> entire dataset formed as the result of a query is returned to a client
>> within a response message. The WS-DAI specification defines a second
>> pattern, indirect data access, where the result of a query is made
>> available as a new data resource, i.e. implementing the factory
>> pattern. This pattern supports third-party delivery, can be used to
>> avoid unnecessary data movement, and allows a client to pull data from
>> a data resource rather than have it returned all at once in a single
>> response message. This access pattern is important in a wide range of
>> scenarios including distributed query processing and providing
>> scalable/reliable data access.
>>
>> - WS-DAI specifications exist for XML and relational data sources, and
>> their adoption will result in applications that follow the WS-DAI
>> approach to using data resources in a service-based setting. There is
>> therefore a need to 'complete' the set of specifications in order to
>> complement the XML and relational realisations, enabling applications
>> and developers familiar with using WS-DAIR and WS-DAIX to interact
>> with RDF(S) data resources using the same approach. Currently, RDF(S)
>> data is widely used and its adoption is growing, this means that the
>> next logical progression is to concentrate DAIS-WG efforts in this
>> area.
>>
>> -  The SPARQL query language is not the only means by which a client
>> may wish to interact with an RDF(S) data resource. The interfaces
>> provided by RDF(S) storage systems, for example the Jena Ontology API,
>> provide a a range of mechanisms for directly manipulating an ontology.
>> As such APIs vary depending on the specific storage system used, for
>> example Oracle RDF, Sesame etc., the WS-DAI-RDF(S) Ontology
>> specification aims to provide a set of ontology handling primitives
>> for interacting with RDF(S) data resources, hiding any syntactic and
>> platform-dependent aspects, enabling their use in an open,
>> interoperable way.
>> --
>>  dais-wg mailing list
>>  dais-wg at ogf.org
>>  http://www.ogf.org/mailman/listinfo/dais-wg
>>
>
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