RE: RSP Data Model

Hi all,
I would like to expand on Emanuele's comment “It will prevent graphs to be interpreted as a form of punctuation [...]”. Punctuations are indeed quite central in this context. Assume that we would like to punctuate the stream following a sequence of timestamped graphs, and let the timestamped graph (g_4,p,t_x) be used as punctuation:
(g_1,p,t_1)
(g_2,p,t_1)
(g_3,p,t_2)
(g_4,p,t_x)

Given that our current definition allows more than one graph to have the same timestamp we would need to additionally define that the timestamp of a punctuation graph needs to be "greater than the upper bound of the bounded substream". In the simple case above this would simply mean t_x > t_2. Is this sufficient for the type of punctuations we have in mind?

Cheers,
Robin


Best regards,
Robin Keskisärkkä
PhD Student

[Linköping University]

Department
s-581 83 Linköping
Mobile: +46 (0)70-4909179
Please visit us at www.liu.se<http://www.liu.se>




From: Abraham Bernstein [mailto:bernstein@ifi.uzh.ch]
Sent: den 12 juni 2015 10:13
To: Emanuele Della Valle
Cc: Gray, Alasdair J G; public-rsp@w3.org
Subject: Re: RSP Data Model

Dear all

One additional comment. I have said previously that defining things in relation to a single timestamp has the huge disadvantage over using intervals. I have encountered the need to trat intervals in almost all real-world scenarios that I have worked with. I know that time stamps are easier, but often neither accurate nor practical.

I hope this helps

Cheers

Avi

ps. One outline of a language that uses intervals rather than timestamps is TEF SPARQL (http://www.merlin.uzh.ch/publication/show/8467)



On 12 Jun 2015, at 09:49, Emanuele Della Valle <emanuele.dellavalle@polimi.it<mailto:emanuele.dellavalle@polimi.it>> wrote:

Dear Alasdair, and all

thanks for the report. I would like to point out that the sentence “There can be multiple graphs with the same timestamp” is, in my opinion, a bad choice. It will prevent graphs to be interpreted as a form of punctuation [1] and this was one of the most important gain of the version of RSP Data Model discussed in Berlin (i.e., graphs with strictly increasing timestamps). The lack of punctuation is a problem of the “traditional" timestamped triples data model where contemporary triples must be admitted.

Best regards,

Emanuele

[1] http://link.springer.com/referenceworkentry/10.1007%2F978-0-387-39940-9_285



On 11 Jun 2015, at 18:37, Gray, Alasdair J G <A.J.G.Gray@hw.ac.uk<mailto:A.J.G.Gray@hw.ac.uk>> wrote:

Hi All,

During the ESWC RSP Workshop we had a breakout group focus on defining the RSP data model. I was charged with the action of updating the semantics document with the agreed model.

You can find the updated data model at
https://github.com/streamreasoning/RSP-QL/blob/master/Semantics.md


Best regards,

Alasdair

--
Alasdair J G Gray
Lecturer, Heriot-Watt University
Web: http://www.alasdairjggray.co.uk<http://www.alasdairjggray.co.uk/>
ORCID: http://orcid.org/0000-0002-5711-4872

Twitter: @gray_alasdair
Telephone: +44 131 451 3429
Office: EM 1.39



We invite research leaders and ambitious early career researchers to join us in leading and driving research in key inter-disciplinary themes. Please see www.hw.ac.uk/researchleaders<http://www.hw.ac.uk/researchleaders> for further information and how to apply.

Heriot-Watt University is a Scottish charity registered under charity number SC000278.


-----------------------------------------------------------------
|  Professor Abraham Bernstein, PhD
|  University of Zürich, Department of Informatics
|  web: http://www.ifi.uzh.ch/ddis/bernstein.html