Re: example of RSP-QL query to kick-off the RSP-QL syntax discussion

Hi Alasdair,
Interesting pont. I don't have an answer to this specific question, but
please consider it is possible to obtain the same result with two separate
queries:
- one that creates a DStream :s1d on :s1 (to create a delay)
- one with a window of size 1h and slide 5 mins on :s1d

Talking about window, I have another question: if windows do not remove
timestamps from the data items, it would be possible to declare windows
over other windows... Is it something that our language would allow?

Regards,

Daniele

2014-11-27 12:04 GMT+00:00 Gray, Alasdair <A.J.G.Gray@hw.ac.uk>:

>  Hi
>
>  Is it possible to have windows that are entirely in the past? For
> example to compare with yesterday’s values we would need something like
>
>  FROM NAMED STREAM s:1 [FROM NOW - 25 HOURS TO NOW - 24 HOURS STEP PT5M] AS :yesterdayOneHourWindow
>
> This is borrowing syntax from SPARQLStream.
>
>  Alasdair
>
>  On 14 Nov 2014, at 20:18, Emanuele Della Valle <
> emanuele.dellavalle@polimi.it> wrote:
>
>  Hi all,
>
>  as promised during today phone-call, I prepared an example of RSP-QL
> query to kick-off the RSP-QL syntax discussion.
>
>  Please find it here:
> https://www.w3.org/community/rsp/wiki/Example_of_RSP-QL_query
>
>  I’m also putting it hereafter just in case you want to directly comment
> it.
>
>  Cheers,
>
>  Emanuele
>
>  ——8——
>
>  This query continuously look for bars where people are falling in love
> like Paolo and Francesca in Dante's Divine Comedy
> <http://en.wikipedia.org/wiki/Francesca_da_Rimini#In_Inferno> because of
> a book by Gallehault <http://en.wikipedia.org/wiki/Galehaut>.
>
>
>  PREFIX e: <http://somevocabulary.org/>
> PREFIX s: <http://someinvasivesensornetwork.org/streams#>
> PREFIX g: <http://somesocialnetwork.org/graphs#>
> PREFIX : <http://acrasycompany.org/rsp>
> REGISTER STREAM :GallehaultWasTheBar
> UNDER ENTAILMENT REGIME <http://www.w3.org/ns/entailment/RIF>
> AS
> FROM STREAM s:1
> FROM NAMED STREAM s:1 [RANGE PT1H STEP PT5M] AS :longWindow
> FROM NAMED STREAM s:1 [RANGE PT10M STEP PT5M] AS :shortWindow
> FROM NAMED GRAPH g:SocialGraph
> FROM GRAPH g:POIs
> CONSTRUCT ISTREAM {
>  ?poi rdf:type :Gallehault ;
>       :count ?howmanycouples ;
>       :for (?somebody ?someoneelse)         
> }
> WHERE {
>  ?poi rdf:type e:bar .
>  STREAM s:1 {
>      { ?somebody e:enters ?poi }
>      SEQ
>      { ?someoneelse ex:enters ?poi } WITHIN PT4H
>  }
>  WINDOW :longWindow {
>      { ?somebody e:isCloseTo ?someoneelse
>        MINUS { ?somebody e:sitsWith ?yetanotherone . FILTER (?yetanotherone != ?someoneelse) }
>      } WITH DURATION ?longtime
>      FILTER (?longtime>"PT30M"^^xsd:duration)
>  }
>  WINDOW :shortWindow {
>      { ?somebody e:exits ?bar} AT ?t1
>      { ?someoneelse e:exits ?bar } AT ?t2
>      FILTER (abs(?t2-?t1)<"PT1M"^^xsd:duration )
>  }
>  GRAPH g:1 {
>      FILTER NOT EXIST { ?somebody e:knows ?someoneelse }
>  }
>  FILTER (?somebody != ?someoneelse)
> }
> AGGREGATE {
>  GROUP BY ?bar
>  COUNT(?somebody) AS ?howmanycouples
> }
>
>  The query checks :
>
>    - over the default graph containing the points of interest (POIs) of
>    http://somesocialnetwork.org/ that the POI is a bar.
>    - over the entire stream from http://someinvasivesensornetwork.org,
>    that pairs of people entered in the poi in different moments within 4
>    hours.
>    - over the same stream, with a long lasting time window of 1 hour,
>    that pairs of those people have been staying close by for at least 30
>    minutes. Note: that this may require some resoning being the property
>    isCloseBy symmetric.
>    - over the same stream but with a short time window of 10 minutes,
>    that the same pairs exit together.
>
> As output, for each bar, it streams out an RDF graph with the list of
> pairs and the total number of pairs that felt in love at each query
> evaluation.
>
> Note that this example query covers features of C-SPARQL, CQELS,
> SPARQL-Stream, EP-SPARQL as well as new features missing in all RSP
> languages:
>
>    -  From C-SPARQL it takes the REGISTER clause, the FROM STREAM clause
>    as dataset clause, the AT clause to access the timestamp (in C-SPARQL, AT
>    is implemented with the timestamp() function) and the aggregates (which are
>    computed in parallel without shrinking the result set, but extending it).
>    - From CQELS it takes the idea of the STREAM keyword in the WHERE
>    clause.
>    - From SPARQL-Stream it takes the ISTREAM clasue that ask the RSP
>    engine to use the R2S operator.
>    - From EP-SPARQL, it takes the SEQ and the WITH DURATION clauses (in
>    EP-SPARQL, WITHIN DURATION is implemented with the getDuration() function).
>
> The new features are:
>
>    - the usage of an IRI tuo identify the query (and its stream of
>    results)
>    - the optional UNDER ENTAILMENT REGIME clause
>    - the FROM NAMED STREAM <<stream iri>> <<window>> AS << window name>>
>    clause in the dataset declaration
>    - the WINDOW keyword in the WHERE clause
>
>
>  --
> Emanuele Della Valle
> DEIB - Politecnico di Milano
> w. http://emanueledellavalle.org
>
>
>       Alasdair J G Gray
>  Lecturer in Computer Science, Heriot-Watt University, UK.
> Email: A.J.G.Gray@hw.ac.uk
> Web: http://www.alasdairjggray.co.uk
> ORCID: http://orcid.org/0000-0002-5711-4872
> Telephone: +44 131 451 3429
> Twitter: @gray_alasdair
>
>
>
>
>
>
>
>
>
>  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 for further information and how to
> apply.
>
>  Heriot-Watt University is a Scottish charity registered under charity
> number SC000278.
>