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Re: R2RML practicability concerns

From: Juan Sequeda <juanfederico@gmail.com>
Date: Wed, 6 Oct 2010 00:17:13 -0500
Message-ID: <AANLkTi=L8Q2UyZR+KmB=pUf+=kV7EbH4FEVcRv8u9y8X@mail.gmail.com>
To: Souripriya Das <souripriya.das@oracle.com>
Cc: Sören Auer <soeren.auer@gmail.com>, RDB2RDF WG <public-rdb2rdf-wg@w3.org>
I was pushing a while back that the default mapping should not only be the
rules to output RDF, but the default mapping itself should be represented in
R2RML itself. With this first draft, I'm sure that Eric, Marcelo and I can
get that done easily

Juan Sequeda
+1-575-SEQ-UEDA
www.juansequeda.com


On Wed, Oct 6, 2010 at 12:12 AM, Souripriya Das
<souripriya.das@oracle.com>wrote:

> I believe that the R2RML mapping language must allow full mapping
> functionality. However, to address the other extreme of the spectrum and
> points in between, R2RML should provide shortcut constructs where
> default/automatic mappings can be specified with very concise mapping
> specification. (Please note, however, that the example we have included in
> the current draft is probably artificially complex because its main purpose
> was to illustrate most if not all functionality allowed by R2RML.)
>
> We will add constructs that will allow minimal mapping specification that
> can be used and also that can be incrementally refined, if necessary.
>
> Thanks,
> - Souri.
>
>
> On 10/5/2010 7:15 PM, Sören Auer wrote:
>
>> Dear all,
>>
>> unfortunately there was not time today during the telco to raise this
>> concern, that is why now by email:
>>
>> When looking at the example I notice, that the relational tables
>> definition would be very concise (~15 lines). The R2RML mapping, however, is
>> very verbose and takes probably 5 times more space.
>>
>> I'm really afraid, that R2RML will be very impractical and has a quite
>> steep learning curve. Even if you have user interfaces which automatize the
>> generation of R2RML, these will have to be understood and modified manually
>> as soon as the DB schema changes. From that perspective, the current draft
>> appears to be quite impractical.
>>
>> Suggestion: do you think it would be possible to follow a convention over
>> configuration approach and only require the user to configure something in
>> case he wants to alter the default behaviour. For example, an
>> rr:Table2TriplesMap based on an rr:logicalTable could be mapped based on
>> reasonable assumptions and maybe a default mapping of DB datatypes to
>> XML-Schema datatypes, instead of having to configure every
>> rr:propertyObjectMaps in addition for every column.
>>
>> I think simplifying things is really crucial, if we want the standard to
>> be quickly and widely adopted.
>>
>> Best,
>>
>> Sören
>>
>>
>
>
Received on Wednesday, 6 October 2010 05:18:07 UTC

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