W3C home > Mailing lists > Public > semantic-web@w3.org > July 2014

Re: An alternative RDF

From: Victor Porton <porton@narod.ru>
Date: Thu, 10 Jul 2014 14:18:40 +0300
To: Michael Brunnbauer <brunni@netestate.de>
Cc: SW-forum Web <semantic-web@w3.org>
Message-Id: <4985471404991120@web14g.yandex.ru>
10.07.2014, 11:26, "Michael Brunnbauer" <brunni@netestate.de>:
> Hello Victor,
>
> what makes you think that RDF should be suited for your task instead of e.G.
> XML and/or relational databases? RDF was not created as another tool to
> handle data and data structures - there are enough of them around. RDF is more
> about knowledge than about data (though the distinction is continuous).
>
> So if you are using RDF for data structures specific to your app, RDF is not
> an obvious choice. Why did you go for it?
>
> Why does your app combine data from different files? How about using named
> graphs instead?

The reason that I choose RDF is because my app combine data from different files.

Below in this message there is presented a solution of my problem in RDF.

> Regards,
>
> Michael Brunnbauer
>
> On Wed, Jul 09, 2014 at 09:59:33PM +0300, Victor Porton wrote:
>>  As you see from my earlier messages to this mailing list, I had a trouble to process data combined from several different RDF files.
>>
>>  Recently I have thought is that (the way I use) RDF is a wrong tool for my task!
>>
>>  Consider this Turtle code:
>>
>>  @prefix : http://portonvictor.org/ns/trans/ .
>>  <http://example.org/the-transformation>
>>          a :transformer ;
>>          dc:description <http://...> ;
>>          # Other Dublin Core metadata.
>>          :source-namespace <...> ;
>>          :target-namespace <...> ;
>>          :precedence <...> ;
>>          :script-data [
>>                  a :xslt ;
>>                  :version "2.0" ;
>>                  :script-url <http://example.org/scripts/foo.xslt> ;
>>                  :transformer-kind :entire ;
>>                  :arguments [
>>                          :argument [
>>                                  :name "debug" ;
>>                                  :value false
>>                          ] ;
>>                          :argument [
>>                                  :name "other" ;
>>                                  :value 123
>>                          ]
>>                  ] ;
>>                  #:initial-context-node ... ; # See XSLT 2.0 spec.
>>                  initial-template "first" ;
>>                  initial-mode: "first" ;
>>                  completeness 0.9 ;
>>                  stability 0.9 ;
>>                  preference 0.9
>>          ] .
>>
>>  The trouble is that there may be no more than one :precedence. If we load data from an other RDF file, nothing prevents them be merged in such as way that there may be more than one :precedence for the same object, so rendering data inconsistent and forcing the programmer (me) to do something with a data which once was consistent but then suddenly became inconsistent.
>>
>>  In my opinion, this trouble is from essence of RDF itself.
>>
>>  We should do something either modifying the RDF specification, or creating a new formal language to describe objects which cannot be merged from several files in an inconsistent way.
>>
>>  One way to solve it inside RDF is to add blank nodes, like:
>>
>>  @prefix : http://portonvictor.org/ns/trans/ .
>>  <http://example.org/the-transformation> :transformation-data [
>>          a :transformer ;
>>          dc:description <http://...> ;
>>          # Other Dublin Core metadata.
>>          :source-namespace <...> ;
>>          :target-namespace <...> ;
>>          :precedence <...> ;
>>          :script-data [
>>                  a :xslt ;
>>                  :version "2.0" ;
>>                  :script-url <http://example.org/scripts/foo.xslt> ;
>>                  :transformer-kind :entire ;
>>                  :arguments [
>>                          :argument [
>>                                  :name "debug" ;
>>                                  :value false
>>                          ] ;
>>                          :argument [
>>                                  :name "other" ;
>>                                  :value 123
>>                          ]
>>                  ] ;
>>                  #:initial-context-node ... ; # See XSLT 2.0 spec.
>>                  initial-template "first" ;
>>                  initial-mode: "first" ;
>>                  completeness 0.9 ;
>>                  stability 0.9 ;
>>                  preference 0.9
>>          ]
>>  ].
>>
>>  This way http://example.org/the-transformation becomes an object which cannot be "amended" into an inconsistent state by loading one more RDF file. We can provide an other data for http://example.org/the-transformation but it would be a separate object, which may have single :precedence, etc. Even if the second object (sharing the same resource URL) is invalid (say has more than one :precedence), the first object (above described) remains valid.
>>
>>  However RDF parsers generate IDs (like _:genid1) where unnamed nodes are inserted. I am not sure whether a non-appropriate information may be inserted from an other RDF file using an ID like _:genid1. (Can it?)
>>
>>  Also the last code example is a little ugly: What is a reason to put the top-level http://example.org/the-transformation inside `:transformation-data [ ... ]` container, while the lower levels of the data tree (as presented above) are not in containers? Is it consistent with intuition?
>>
>>  So, we need to decide whether we can store such objects in RDF or should RDF be somehow amended or even replaced with an other standard. What I have described above is a serious fundamental problem and it needs to be addressed!
>>
>>  --
>>  Victor Porton - http://portonvictor.org
>
> --
> ++  Michael Brunnbauer
> ++  netEstate GmbH
> ++  Geisenhausener Straße 11a
> ++  81379 München
> ++  Tel +49 89 32 19 77 80
> ++  Fax +49 89 32 19 77 89
> ++  E-Mail brunni@netestate.de
> ++  http://www.netestate.de/
> ++
> ++  Sitz: München, HRB Nr.142452 (Handelsregister B München)
> ++  USt-IdNr. DE221033342
> ++  Geschäftsführer: Michael Brunnbauer, Franz Brunnbauer
> ++  Prokurist: Dipl. Kfm. (Univ.) Markus Hendel

--
Victor Porton - http://portonvictor.org
Received on Thursday, 10 July 2014 11:19:13 UTC

This archive was generated by hypermail 2.3.1 : Tuesday, 1 March 2016 07:42:52 UTC