[Bigdata-developers] RDR problems

[Johannes F. <joh...@st...>]

Hello,

I'm facing the following problems with RDR using blazegraph Build 
Version 1.5.3.
CASE 1 and CASE 2 are major problems. CASE 3 is just a SPARQL* parser 
issue and there is a workaround by using BIND statements instead.

In CASE 1 I want to reify a reified statement. In the SPARQL* paper 
(referenced on the RDR wiki site) the EBNF definition of a TRefPattern 
is recursive.
And there is a explicit note on nested triple reference patterns. So 
this should work. Querying such triple data using BIND statements works 
(more precisely: there are no errors), but unfortunately I don't know 
how to import data consisting of nested reified triples. Nesting the "<< 
 >>"-statements doesn't work, neither in Turtle* nor in SPARQL*.

In CASE 2 I want to use SPARQL update to insert or remove a simple 
reified statement. But it seems that this not implemented in blazegraph, 
because it's rejecting a bunch of queries
due to parser errors. But then my question is: How to remove or change a 
reified triple statement? I'm considering to use blazegraph for large 
scale use, so deleting the whole KB and reimporting it is not feasible.

I appreciate any help you can provide.

Regards
Johannes


=================== SPARQL*  - CASE 1 =============================
Prefix : <http://example.org/ns#>
Select * where
{
   BIND( <<:Bob :isMarriedTo :Alice >> as ?t) .
   BIND( <<?t   :validUntil  "2015-12-01" >> as ?t2) .
   ?t2  :crawledOn    "2015-12-07" .
}

=================== Turtle*  - CASE 1 =============================
****NOT WORKING****
@prefix : <http://example.org/ns#> .
<< <<:Bob :isMarriedTo :Alice >> :validUntil "2015-12-01" >> :crawledOn  
"2015-12-07"


=================== SPARQL*  - CASE 2a) b) c) d) 
=============================
****NOT WORKING**** a) *****
Prefix : <http://example.org/ns#>
INSERT DATA
{
   <<:Bob :isMarriedTo :Alice>> :validUntil "2015-12-01".
}

****NOT WORKING**** b) *****
Prefix : <http://example.org/ns#>
INSERT { <<:Bob :isMarriedTo :Alice>> :validUntil "2015-12-01". } WHERE {}


****NOT WORKING**** c) *****
Prefix : <http://example.org/ns#>
DELETE { <<:Bob :isMarriedTo :Alice>> :validUntil "2015-12-01". } WHERE {}

****NOT WORKING**** d) *****
Prefix : <http://example.org/ns#>
DELETE { BIND( <<:Bob :isMarriedTo :Alice >> as ?t) . ?t :validUntil  
"2015-12-01". } WHERE {}

=================== SPARQL*  - CASE 3 =============================
****NOT WORKING****
Prefix : <http://example.org/ns#>
Select * where
{
   <<:Bob :isMarriedTo :Alice>> ?x <<:a :b :c>> .
}
=================== Turtle*  - CASE 3 =============================
****BUT WORKING in Turtle* ****
@prefix : <http://example.org/ns#> .
<<:Bob :isMarriedTo :Alice >> :x <<:a :b :c>> .