dotnetrdf-support — User Help and Support

Re: [dotNetRDF-Support] Load performance

[<mar...@ko...>]

Hi Rob,

Thanks the advice and good ideas.

I tried using a custom parser to load the Graph (see below) that exploits 
the regular, relatively flat structure of my RDF document.  That reduces 
the load time down to around 7.6 seconds (from around 11 seconds); setting 
Options.FullTripleIndexing to false shaved another second plus off the 
time.  If there's something I can do to make the simple parser run faster, 
please let me know.

The time to execute the LINQ queries remains very fast with the dotNetRDF 
library, even without the full indexing, but I think I would need to 
further halve the load time to get to a break-even point with respect to 
just using XElement.Load().  Of course, if we were doing lots of queries, 
then the load time would become inconsequential.

Thanks again,
-Mark

//   code makes no pretense of being robust against RDF not conforming to 
its expectations!!!
//  Prefixes.rdf defined elsewhere:        public static readonly 
XNamespace rdf = "http://www.w3.org/1999/02/22-rdf-syntax-ns#";

            foreach (XElement elem in xElem.Descendants(Prefixes.rdf + 
"Description"))
            {
                String subjName = elem.Attribute(Prefixes.rdf + "about"
).Value;
                foreach (XElement child in elem.Elements())
                {
                    INode obj;
                    IUriNode subj  = g.CreateUriNode(UriFactory
.Create(subjName));
                    IUriNode pred = g.CreateUriNode(UriFactory
.Create(child.Name.NamespaceName + child.Name.LocalName));
                    if (child.HasAttributes)
                    {
                        obj = g.CreateUriNode(UriFactory
.Create(child.Attribute(Prefixes.rdf + "resource").Value));
                    }
                    else
                    {
                        obj = g.CreateLiteralNode(child.Value);
                    }
                    Triple t = new Triple(subj, pred, obj);
                    g.Assert(t);
                }
            }



From:
Rob Vesse <rv...@do...>
To:
dotNetRDF User Help and Support <dot...@li...>
Date:
02/12/2013 05:44 PM
Subject:
Re: [dotNetRDF-Support] Load performance



Hey Mark

I am not sure that we can really provide you with that much help on this 
but I will try anyway.

I think with the existing parser architecture it will be quite hard to get 
within a small multiplier of the XElement.Load() time.  RDF/XML parsing is 
a two stage process based upon the RDF/XML specification, we first convert 
the XML into parser events (either via XmlReader or XmlDocument depending 
on configuration) and then we process those events to generate triples. 
There is also an awful lot of verification and parsing steps that go on in 
the RDF/XML parser.

Is the XElement.Load based code something you would be able to share at 
all?  It sounds like it is almost certainly possible to build an improved 
event generating stage for the parser which may make a big difference to 
the performance of the parser.  Even if this can only be used as you 
suggest for simple regular RDF/XML having that option available to users 
would be quite valuable.

In the meantime there are a couple of things you could try:

1 ? Do you need full indexes?

Are you queries primarily on single terms of the triple?  If so setting 
Options.FullTripleIndexing to false and then creating a Graph and loading 
should be faster than full indexing but still gives you partial indexes. 
Compound lookups are still partial linear scans but will be faster than 
the full linear scans the NonIndexedGraph has to do.

Alternatively would the ability to select which indexes you need be 
valuable so that only those were built?  This is certainly a feature we 
could add for the next release.

2 ? Use a custom IRdfHandler

If you can handle your queries with some simpler data structures then 
perhaps you can use a custom IRdfHandler and pass this to the parser 
instead.  This interface gives you control over what happens to triples 
and whether the parser should continue each time you see a triple.  You 
can extend BaseRdfHandler to get most of the implementation for free.

See http://www.dotnetrdf.org/content.asp?pageID=Handlers%20API for more 
documentation on this

Hope this helps, please let us know if you need more information,

Rob

From: <mar...@ko...>
Reply-To: dotNetRDF User Help and Support <
dot...@li...>
Date: Tuesday, February 12, 2013 10:12 AM
To: <dot...@li...>
Subject: [dotNetRDF-Support] Load performance

I'm wondering how to best optimize the load performance of dotNetRDF.  

I have an RDF/XML (test) file containing the equivalent of about 316000 
n-triples statements pertaining to about 21000 resources.  The RDF is 
highly regular, and limited to a subset of full RDF/XML, having the 
following structure:

<rdf:Description rdf:about="....">
   <rdf:type rdf:resource="....">
   <dc:subject> ... </dc:subject>
   ... {small but variable number of other properties }

</rdf:Description>
...

My program reads the RDF and does some LINQ-based queries against it.   

It takes about 11 seconds to load the RDF/XML into a Graph; given the 
loaded graph, the LINQ queries take about 24 milliseconds.

As a comparison point, though, I tried to see what the performance would 
be if I used the .NET XElement.Load function, exploiting the fact that my 
XML has a very regular structure (no lists/blank nodes/nested resources).  
In that case, it takes about 400 milliseconds to load the XML into a 
simple homebrew  triple class structure (no indices); my equivalent LINQ 
queries then take about 200 milliseconds.  Of course, that approach only 
works for a particular RDF/XML structure, and it will start to break down 
as I do more & more queries.

Clearly, if I were to do lots of query operations, the cost of the initial 
load by the dotNetRDF library would be better amortized, and I would start 
to reap the benefits of having the Graph structure.  However, given that I 
only want to do a relatively small number of queries, I'm wondering if 
there's anything I can do to improve the load performance to close the 
gap.   I tried a few things: using NonIndexedGraph (reduced load time down 
to around 8.6 seconds, while bringing my query time up to 1.1 seconds) and 
using Turtle w/ NonIndexGraph (reduced load time to 5.6 seconds), but I'd 
like to get within a small multiplier of the XElement.Load time if 
possible, while preserving the benefit of indexing.

-Mark







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Re: [dotNetRDF-Support] Load performance

[Rob V. <rv...@do...>]

Hey Mark

I am not sure that we can really provide you with that much help on this but
I will try anyway.

I think with the existing parser architecture it will be quite hard to get
within a small multiplier of the XElement.Load() time.  RDF/XML parsing is a
two stage process based upon the RDF/XML specification, we first convert the
XML into parser events (either via XmlReader or XmlDocument depending on
configuration) and then we process those events to generate triples.  There
is also an awful lot of verification and parsing steps that go on in the
RDF/XML parser.

Is the XElement.Load based code something you would be able to share at all?
It sounds like it is almost certainly possible to build an improved event
generating stage for the parser which may make a big difference to the
performance of the parser.  Even if this can only be used as you suggest for
simple regular RDF/XML having that option available to users would be quite
valuable.

In the meantime there are a couple of things you could try:

1 ­ Do you need full indexes?

Are you queries primarily on single terms of the triple?  If so setting
Options.FullTripleIndexing to false and then creating a Graph and loading
should be faster than full indexing but still gives you partial indexes.
Compound lookups are still partial linear scans but will be faster than the
full linear scans the NonIndexedGraph has to do.

Alternatively would the ability to select which indexes you need be valuable
so that only those were built?  This is certainly a feature we could add for
the next release.

2 ­ Use a custom IRdfHandler

If you can handle your queries with some simpler data structures then
perhaps you can use a custom IRdfHandler and pass this to the parser
instead.  This interface gives you control over what happens to triples and
whether the parser should continue each time you see a triple.  You can
extend BaseRdfHandler to get most of the implementation for free.

See http://www.dotnetrdf.org/content.asp?pageID=Handlers%20API for more
documentation on this

Hope this helps, please let us know if you need more information,

Rob

From:  <mar...@ko...>
Reply-To:  dotNetRDF User Help and Support
<dot...@li...>
Date:  Tuesday, February 12, 2013 10:12 AM
To:  <dot...@li...>
Subject:  [dotNetRDF-Support] Load performance

> I'm wondering how to best optimize the load performance of dotNetRDF.
> 
> I have an RDF/XML (test) file containing the equivalent of about 316000
> n-triples statements pertaining to about 21000 resources.  The RDF is highly
> regular, and limited to a subset of full RDF/XML, having the following
> structure:
> 
> <rdf:Description rdf:about="....">
>    <rdf:type rdf:resource="....">
>    <dc:subject> ... </dc:subject>
>    ... {small but variable number of other properties }
> 
> </rdf:Description>
> ...
> 
> My program reads the RDF and does some LINQ-based queries against it.
> 
> It takes about 11 seconds to load the RDF/XML into a Graph; given the loaded
> graph, the LINQ queries take about 24 milliseconds.
> 
> As a comparison point, though, I tried to see what the performance would be if
> I used the .NET XElement.Load function, exploiting the fact that my XML has a
> very regular structure (no lists/blank nodes/nested resources).   In that
> case, it takes about 400 milliseconds to load the XML into a simple homebrew
> triple class structure (no indices); my equivalent LINQ queries then take
> about 200 milliseconds.  Of course, that approach only works for a particular
> RDF/XML structure, and it will start to break down as I do more & more
> queries.
> 
> Clearly, if I were to do lots of query operations, the cost of the initial
> load by the dotNetRDF library would be better amortized, and I would start to
> reap the benefits of having the Graph structure.  However, given that I only
> want to do a relatively small number of queries, I'm wondering if there's
> anything I can do to improve the load performance to close the gap.   I tried
> a few things: using NonIndexedGraph (reduced load time down to around 8.6
> seconds, while bringing my query time up to 1.1 seconds) and using Turtle w/
> NonIndexGraph (reduced load time to 5.6 seconds), but I'd like to get within a
> small multiplier of the XElement.Load time if possible, while preserving the
> benefit of indexing.
> 
> -Mark
> 
> 
> 
> 
> 
> 
> 
> ------------------------------------------------------------------------------
> Free Next-Gen Firewall Hardware Offer Buy your Sophos next-gen firewall before
> the end March 2013 and get the hardware for free! Learn more.
> http://p.sf.net/sfu/sophos-d2d-feb____________________________________________
> ___ dotNetRDF-Support mailing list dot...@li...
> https://lists.sourceforge.net/lists/listinfo/dotnetrdf-support

Re: [dotNetRDF-Support] Load performance

[altaf h. <alt...@ya...>]

Hi Mark, 
Hope support team will give a you a good answer. They are the perfect ones to provide the answers.

However, I think you can use Parallel Linq (PLINQ). This will clearly reduce the some queries on your XML.

Look Here,
http://msdn.microsoft.com/en-us/library/dd997425.aspx 

Kind Regards,


Altaf Hussain
Graduate Student Researcher
Centre for Logic and Information


Graduate Student (CS) and Teaching Assistant
St. Francis Xavier University
Alumni' 02 Batch, Dept. of Computer Science and Engineering 
Shah Jalal University of Science and Technology

Blog: http://altafhussainbd.wordpress.com



________________________________
 From: "mar...@ko..." <mar...@ko...>
To: dot...@li... 
Sent: Tuesday, February 12, 2013 2:12 PM
Subject: [dotNetRDF-Support] Load performance
 

I'm wondering how to best optimize the
load performance of dotNetRDF.   

I have an RDF/XML (test) file containing
the equivalent of about 316000 n-triples statements pertaining to about
21000 resources.  The RDF is highly regular, and limited to a subset
of full RDF/XML, having the following structure: 

<rdf:Description rdf:about="...."> 
   <rdf:type rdf:resource="...."> 
   <dc:subject> ...
</dc:subject> 
   ... {small but variable
number of other properties } 

</rdf:Description> 
... 

My program reads the RDF and does some
LINQ-based queries against it.    

It takes about 11 seconds to load the
RDF/XML into a Graph; given the loaded graph, the LINQ queries take about
24 milliseconds. 

As a comparison point, though, I tried
to see what the performance would be if I used the .NET XElement.Load function,
exploiting the fact that my XML has a very regular structure (no lists/blank
nodes/nested resources).   In that case, it takes about 400 milliseconds
to load the XML into a simple homebrew  triple class structure (no
indices); my equivalent LINQ queries then take about 200 milliseconds.
 Of course, that approach only works for a particular RDF/XML structure,
and it will start to break down as I do more & more queries. 

Clearly, if I were to do lots of query
operations, the cost of the initial load by the dotNetRDF library would
be better amortized, and I would start to reap the benefits of having the
Graph structure.  However, given that I only want to do a relatively
small number of queries, I'm wondering if there's anything I can do to
improve the load performance to close the gap.   I tried a few things:
using NonIndexedGraph (reduced load time down to around 8.6 seconds, while
bringing my query time up to 1.1 seconds) and using Turtle w/ NonIndexGraph
(reduced load time to 5.6 seconds), but I'd like to get within a small
multiplier of the XElement.Load time if possible, while preserving the
benefit of indexing. 

-Mark 








------------------------------------------------------------------------------
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_______________________________________________
dotNetRDF-Support mailing list
dot...@li...
https://lists.sourceforge.net/lists/listinfo/dotnetrdf-support

[dotNetRDF-Support] Load performance

[<mar...@ko...>]

I'm wondering how to best optimize the load performance of dotNetRDF. 

I have an RDF/XML (test) file containing the equivalent of about 316000 
n-triples statements pertaining to about 21000 resources.  The RDF is 
highly regular, and limited to a subset of full RDF/XML, having the 
following structure:

<rdf:Description rdf:about="....">
   <rdf:type rdf:resource="....">
   <dc:subject> ... </dc:subject>
   ... {small but variable number of other properties }

</rdf:Description>
...

My program reads the RDF and does some LINQ-based queries against it. 

It takes about 11 seconds to load the RDF/XML into a Graph; given the 
loaded graph, the LINQ queries take about 24 milliseconds.

As a comparison point, though, I tried to see what the performance would 
be if I used the .NET XElement.Load function, exploiting the fact that my 
XML has a very regular structure (no lists/blank nodes/nested resources).  
In that case, it takes about 400 milliseconds to load the XML into a 
simple homebrew  triple class structure (no indices); my equivalent LINQ 
queries then take about 200 milliseconds.  Of course, that approach only 
works for a particular RDF/XML structure, and it will start to break down 
as I do more & more queries.

Clearly, if I were to do lots of query operations, the cost of the initial 
load by the dotNetRDF library would be better amortized, and I would start 
to reap the benefits of having the Graph structure.  However, given that I 
only want to do a relatively small number of queries, I'm wondering if 
there's anything I can do to improve the load performance to close the 
gap.   I tried a few things: using NonIndexedGraph (reduced load time down 
to around 8.6 seconds, while bringing my query time up to 1.1 seconds) and 
using Turtle w/ NonIndexGraph (reduced load time to 5.6 seconds), but I'd 
like to get within a small multiplier of the XElement.Load time if 
possible, while preserving the benefit of indexing.

-Mark

Re: [dotNetRDF-Support] sparql query with prefix in dotnetrdf doesnot work but without prefix it works

[Rob V. <rv...@do...>]

You haven't really asked a proper question here?

What is the query that works and what is the one that doesn't work?

Also what is your data?

It is quite possible that your query simply isn't querying the data you
think it is, this is a result of how SPARQL deals with datasets.

Try changing your code so instead of creating a TripleStore and adding a
graph to it you call ExecuteQuery() on the graph directly.  Another thing to
try is to rewrite your query like so:

PREFIX pre:<http://www.cbcs.com/ontologies/cbcs.owl#>
SELECT ?X ?Y WHERE { GRAPH ?g { ?X pre:hasInstitutes ?Y . } }

If you provide more information we may actually be able to help you properly

Rob

From:  mital <kap...@gm...>
Reply-To:  dotNetRDF User Help and Support
<dot...@li...>
Date:  Friday, February 8, 2013 4:58 AM
To:  <dot...@li...>
Subject:  [dotNetRDF-Support] sparql query with prefix in dotnetrdf doesnot
work but without prefix it works

>  
> my main function says--
>  
> static void Main(string[] args)
>         {
>  
>             Graph g = new Graph();
>             FileLoader.Load(g, "\\cbcs.owl");
>  
>             
>             TripleStore store = new TripleStore();
>             store.Add(g);
>             //Object results = store.ExecuteQuery("SELECT * WHERE { { ?s ?p ?o
> } UNION { GRAPH ?g { ?s ?p ?o } } }");
>  
>             Object results = store.ExecuteQuery("PREFIX
> pre:<http://www.cbcs.com/ontologies/cbcs.owl#>" + "SELECT ?X ?Y WHERE { ?X
> pre:hasInstitutes ?Y .}");
>             SparqlResultSet rset = (SparqlResultSet)results;
>  
>             //Enumerating via the Results property
>             foreach (SparqlResult result in rset.Results)
>             {
>                 Console.WriteLine(result.ToString());
>             }
>  
>  
>             Console.WriteLine("hello");
>             Console.ReadLine();
>         }
>  
>  
> but it doesnt display the answer if my query is simple and without answer it
> works but with prefix it doesnt please help
> ------------------------------------------------------------------------------
> Free Next-Gen Firewall Hardware Offer Buy your Sophos next-gen firewall before
> the end March 2013 and get the hardware for free! Learn more.
> http://p.sf.net/sfu/sophos-d2d-feb____________________________________________
> ___ dotNetRDF-Support mailing list dot...@li...
> https://lists.sourceforge.net/lists/listinfo/dotnetrdf-support

[dotNetRDF-Support] sparql query with prefix in dotnetrdf doesnot work but without prefix it works

[mital <kap...@gm...>]

 

my main function says--

 

static void Main(string[] args)

        {

 

            Graph g = new Graph();

            FileLoader.Load(g, "\\cbcs.owl");

 

            

            TripleStore store = new TripleStore();

            store.Add(g);

            //Object results = store.ExecuteQuery("SELECT * WHERE { { ?s ?p
?o } UNION { GRAPH ?g { ?s ?p ?o } } }");

 

            Object results = store.ExecuteQuery("PREFIX
pre:<http://www.cbcs.com/ontologies/cbcs.owl#>" + "SELECT ?X ?Y WHERE { ?X
pre:hasInstitutes ?Y .}");

            SparqlResultSet rset = (SparqlResultSet)results;

 

            //Enumerating via the Results property

            foreach (SparqlResult result in rset.Results)

            {

                Console.WriteLine(result.ToString());

            }

 

 

            Console.WriteLine("hello");

            Console.ReadLine();

        }

 

 

but it doesnt display the answer if my query is simple and without answer it
works but with prefix it doesnt please help

Re: [dotNetRDF-Support] OntologyResource(INode resource, IGraph graph)

[Yossi C. <yos...@li...>]

Greate, Thanks.

Date: Thu, 7 Feb 2013 10:17:22 -0800
From: rv...@do...
To: dot...@li...
Subject: Re: [dotNetRDF-Support] OntologyResource(INode resource, IGraph graph)

Hi Yossi
Answers inline:
From:  Yossi Cohen <yos...@li...>
Reply-To:  dotNetRDF User Help and Support <dot...@li...>
Date:  Tuesday, February 5, 2013 10:30 AM
To:  DotNetRDF mailing-list <dot...@li...>
Subject:  [dotNetRDF-Support] OntologyResource(INode resource, IGraph graph)

Hi, 
Couple of (related?) questions:
1. Should an OntologyResource (represented by an INode)  have a different graph then its representative resource?
No but that is not forbidden per se, may just lead to unexpected behavior though.  If you have a specific example where this can happen that would be useful

2. When working with StoreGraphPersistenceWrapper (that implements IGraph) one could do something like this:    IGraph g = new StoreGraphPersistenceWrapper(...)    INode resource = g.CreateUriNode(some uri)    ...    do somthing like: make a query which returns SparqlResult    than, do:    INode node2 = result[0].CopyNode(g) --> (which copies a node with the underlining graph and not with the wrapper.)
    Leading to tow nodes (resource & node2) which have a different graph!
    When I'm working with a wrapper graph it is an IGraph and I expect the xxx.CopyNode(g) to return a node     within the graph (g) supplied in the argument.
The problem is the way CopyNode() works is slightly funky, its not really a bug per se because it has to work the way it does or we run into all sorts of problems trying to do SPARQL updates properly.  Ultimately the problem boils down to a somewhat ill-advised design decision to scope nodes to graphs 4 years ago when I originally started the project which then necessitates this CopyNode() behavior.
Eventually in 2.0 this will be removed so the whole CopyNode() functionality will become defunct and nodes can be freely moved around wherever you want.
Rob


Thanks, Yossi.
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Re: [dotNetRDF-Support] OntologyResource(INode resource, IGraph graph)

[Rob V. <rv...@do...>]

Hi Yossi

Answers inline:

From:  Yossi Cohen <yos...@li...>
Reply-To:  dotNetRDF User Help and Support
<dot...@li...>
Date:  Tuesday, February 5, 2013 10:30 AM
To:  DotNetRDF mailing-list <dot...@li...>
Subject:  [dotNetRDF-Support] OntologyResource(INode resource, IGraph graph)

> Hi, 
> 
> Couple of (related?) questions:
> 
> 1. Should an OntologyResource (represented by an INode)  have a different
> graph then its representative resource?

No but that is not forbidden per se, may just lead to unexpected behavior
though.  If you have a specific example where this can happen that would be
useful

> 
> 2. When working with StoreGraphPersistenceWrapper (that implements IGraph) one
> could do something like this:
>     IGraph g = new StoreGraphPersistenceWrapper(...)
>     INode resource = g.CreateUriNode(some uri)
>     ...
>     do somthing like: make a query which returns SparqlResult
>     than, do:
>     INode node2 = result[0].CopyNode(g) --> (which copies a node with the
> underlining graph and not with the wrapper.)
> 
>     Leading to tow nodes (resource & node2) which have a different graph!
> 
>     When I'm working with a wrapper graph it is an IGraph and I expect the
> xxx.CopyNode(g) to return a node
>     within the graph (g) supplied in the argument.

The problem is the way CopyNode() works is slightly funky, its not really a
bug per se because it has to work the way it does or we run into all sorts
of problems trying to do SPARQL updates properly.  Ultimately the problem
boils down to a somewhat ill-advised design decision to scope nodes to
graphs 4 years ago when I originally started the project which then
necessitates this CopyNode() behavior.

Eventually in 2.0 this will be removed so the whole CopyNode() functionality
will become defunct and nodes can be freely moved around wherever you want.

Rob


> 
> Thanks, 
> Yossi.
> 
>        
> ------------------------------------------------------------------------------
> Free Next-Gen Firewall Hardware Offer Buy your Sophos next-gen firewall before
> the end March 2013 and get the hardware for free! Learn more.
> http://p.sf.net/sfu/sophos-d2d-feb____________________________________________
> ___ dotNetRDF-Support mailing list dot...@li...
> https://lists.sourceforge.net/lists/listinfo/dotnetrdf-support

[dotNetRDF-Support] OntologyResource(INode resource, IGraph graph)

[Yossi C. <yos...@li...>]

Hi, 
Couple of (related?) questions:
1. Should an OntologyResource (represented by an INode)  have a different graph then its representative resource?
2. When working with StoreGraphPersistenceWrapper (that implements IGraph) one could do something like this:    IGraph g = new StoreGraphPersistenceWrapper(...)    INode resource = g.CreateUriNode(some uri)    ...    do somthing like: make a query which returns SparqlResult    than, do:    INode node2 = result[0].CopyNode(g) --> (which copies a node with the underlining graph and not with the wrapper.)
    Leading to tow nodes (resource & node2) which have a different graph!
    When I'm working with a wrapper graph it is an IGraph and I expect the xxx.CopyNode(g) to return a node     within the graph (g) supplied in the argument.
Thanks, Yossi.
 		 	   		  

Re: [dotNetRDF-Support] AllegroGraphConnector & IUpdateableStorage

[Yossi C. <yos...@li...>]

Okay, Thanks.
Date: Tue, 5 Feb 2013 09:43:07 +0000
From: rv...@do...
To: dot...@li...
Subject: Re: [dotNetRDF-Support] AllegroGraphConnector & IUpdateableStorage

Yes I guess it should, the connector was developed for 3.x and then later updated for 4.0 at which point I don't believe it supported SPARQL update.
It should be relatively easy to add support for updates, filed as CORE-308
Note that as a workaround you can use GenericUpdateProcessor to apply updates over an AllegroGraphConnector.  Then once an updated version of dotNetRDF with IUpdateableStorage supported on AllegroGraphConnector is available you won't need to change your code since GenericUpdateProcessor defers to the provided update implementation if the IStorageProvider instance implements IUpdateableStorage
Rob
From:  Yossi Cohen <yos...@li...>
Reply-To:  dotNetRDF User Help and Support <dot...@li...>
Date:  Tuesday, February 5, 2013 11:30 AM
To:  DotNetRDF mailing-list <dot...@li...>
Subject:  SPAM-LOW:  [dotNetRDF-Support] AllegroGraphConnector & IUpdateableStorage

Shouldn't AllegroGraphConnector implement IUpdateableStorage ? 		 	   		  ------------------------------------------------------------------------------
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Re: [dotNetRDF-Support] RULEBASE support in Sparql Parser

[Rob V. <rv...@do...>]

Your query appears to use several non-standard SPARQL features that I have
never encountered before.  Setting the syntax to Extended only enables
syntax extensions we have implemented not arbitrary extensions.

RULEBASE is not a standard feature and a quick Google search didn't tell me
where it comes from?

Also what is the following supposed to be?

<ReadTagList>( ?oref1,  ?oref1ts,  ?o1,  ?o1Status)

It looks like some sort of extended syntax (again I don't know where from)
which would also be rejected?

What tools/product do your SPARQL queries originate from?

We implement SPARQL 1.0 and SPARQL 1.1 per the standards (and are 100%
compliant with those), the extras in the extended syntax are primarily
leftovers from the transitional period when the features of SPARQL 1.1 were
still under development and will most likely be removed in the long term.

Rob

From:  Madhanmohan Savadamuthu <erm...@gm...>
Reply-To:  dotNetRDF User Help and Support
<dot...@li...>
Date:  Sunday, February 3, 2013 12:59 PM
To:  <dot...@li...>
Subject:  [dotNetRDF-Support] RULEBASE support in Sparql Parser

> Folks,
>  
> I have written a small program to parse SPARQL query. I want to make sure that
> SPARQL syntax is correct and also want to parse out all variables. Below is
> the code I used.
>  
> SparqlQueryParser
>  parser = new SparqlQueryParser();
> 
> parser.SyntaxMode =
> SparqlQuerySyntax.Extended;
> 
> SparqlQuery q = parser.ParseFromString(txtBoxSparql.Text.Trim());
> When I pass below SPARQL query, I am getting error that 'Rulebase' is not
> valid.  Below is my SPARQL query. Can some one help me?
>  
> PREFIX rdf: <http://www.w3.org/2000/01/rdf-schema#>
> RULEBASE <DefaultDataBindingRules>
> SELECT <http://www.abc.com/on/sam#Le> ?acLabel ?o ?oLabel   ?o1 ?o1Status
> ?oref1 ?oref1Label ?oref1ts FROM <DataBinding>
> WHERE { 
> OPTIONAL {<http://www.abc.com/on/sam#Le> rdf:label ?acLabel.}
> <http://www.abc.com/on/sam#Le> <http://www.abc.com/on#cc.dd> ?o.
> ?o rdf:label ?oLabel.
> ?o <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> ?oType.
> FILTER(?oType=<http://www.abc.com/on#PP_WW>).
> OPTIONAL {?o <http://www.abc.com/on#ww.gg.rr>  ?oref1   }
> <ReadTagList>( ?oref1,  ?oref1ts,  ?o1,  ?o1Status).
> }
> order by asc(  ?o1)
>  
>  
> 
> 
> -- 
> Thanks and Regards,
> Madhanmohan S 
> ------------------------------------------------------------------------------
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> https://lists.sourceforge.net/lists/listinfo/dotnetrdf-support

Re: [dotNetRDF-Support] AllegroGraphConnector & IUpdateableStorage

[Rob V. <rv...@do...>]

Yes I guess it should, the connector was developed for 3.x and then later
updated for 4.0 at which point I don't believe it supported SPARQL update.

It should be relatively easy to add support for updates, filed as CORE-308
<http://dotnetrdf.org/tracker/Issues/IssueDetail.aspx?id=308>

Note that as a workaround you can use GenericUpdateProcessor to apply
updates over an AllegroGraphConnector.  Then once an updated version of
dotNetRDF with IUpdateableStorage supported on AllegroGraphConnector is
available you won't need to change your code since GenericUpdateProcessor
defers to the provided update implementation if the IStorageProvider
instance implements IUpdateableStorage

Rob

From:  Yossi Cohen <yos...@li...>
Reply-To:  dotNetRDF User Help and Support
<dot...@li...>
Date:  Tuesday, February 5, 2013 11:30 AM
To:  DotNetRDF mailing-list <dot...@li...>
Subject:  SPAM-LOW:  [dotNetRDF-Support] AllegroGraphConnector &
IUpdateableStorage

> Shouldn't AllegroGraphConnector implement IUpdateableStorage ?
> ------------------------------------------------------------------------------
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> ___ dotNetRDF-Support mailing list dot...@li...
> https://lists.sourceforge.net/lists/listinfo/dotnetrdf-support

[dotNetRDF-Support] AllegroGraphConnector & IUpdateableStorage

[Yossi C. <yos...@li...>]

Shouldn't AllegroGraphConnector implement IUpdateableStorage ? 		 	   		  

[dotNetRDF-Support] RULEBASE support in Sparql Parser

[Madhanmohan S. <erm...@gm...>]

Folks,

I have written a small program to parse SPARQL query. I want to make sure
that SPARQL syntax is correct and also want to parse out all variables.
Below is the code I used.


SparqlQueryParser parser = new SparqlQueryParser();

parser.SyntaxMode = SparqlQuerySyntax.Extended;

SparqlQuery q = parser.ParseFromString(txtBoxSparql.Text.Trim());
When I pass below SPARQL query, I am getting error that 'Rulebase' is not
valid.  Below is my SPARQL query. Can some one help me?

PREFIX rdf: <http://www.w3.org/2000/01/rdf-schema#>
RULEBASE <DefaultDataBindingRules>
SELECT <http://www.abc.com/on/sam#Le> ?acLabel ?o ?oLabel   ?o1 ?o1Status
?oref1 ?oref1Label ?oref1ts FROM <DataBinding>
WHERE {
OPTIONAL {<http://www.abc.com/on/sam#Le> rdf:label ?acLabel.}
<http://www.abc.com/on/sam#Le> <http://www.abc.com/on#cc.dd> ?o.
?o rdf:label ?oLabel.
?o <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> ?oType.
FILTER(?oType=<http://www.abc.com/on#PP_WW>).
OPTIONAL {?o <http://www.abc.com/on#ww.gg.rr>  ?oref1   }
<ReadTagList>( ?oref1,  ?oref1ts,  ?o1,  ?o1Status).
}
order by asc(  ?o1)




-- 
Thanks and Regards,
Madhanmohan S

[dotNetRDF-Support] dotNetRDF 0.9.0 RC 4 Released

[Rob V. <rv...@do...>]

We are pleased to announce the release of dotNetRDF 0.9.0 RC 4 available
now from all the usual locations:

Project Website - 
http://www.dotnetrdf.org/content.asp?pageID=Download%20dotNetRDF
SoureForge - http://www.sourceforge.net/project/dotnetrdf
CodePlex - http://dotnetrdf.codeplex.com
BitBucket - http://bitbucket.org/dotnetrdf/dotnetrdf/downloads
NuGet - http://nuget.org/packages/dotNetRDF/

This is primarily a maintenance release, it resolves a variety of bugs
including various SPARQL bugs, some parser bugs and adds a workaround for
HTTP servers which don't perform HTTP authentication nicely.

It is intended to be a final release candidate before a stable 1.0.0
release in the next couple of months.  We would appreciate it if people in
the community could test this build as much as possible and report any
issues they encounter.

As always thanks to everyone in the community who reported issues or made
suggestions for improvements.  Also many thanks to our developers for
their continued hard work.

Rob Vesse

Re: [dotNetRDF-Support] sparql query with prefix doesnot work in dotnetrdf but without prefix works plz help

[Rob V. <rv...@do...>]

Hi Jasmine

At it stands your question is unanswerable since you haven't provided enough
information:

1. What is your data?  Please include it (if it is small) or a snippet of it
containing some sample data you were expecting to match
2. You mention a query that works and one that doesn't ­ please show these
queries on their own separate from your code sample
Rob 

From:  Jasmine Sirja <jas...@gm...>
Reply-To:  dotNetRDF User Help and Support
<dot...@li...>
Date:  Thursday, January 31, 2013 11:56 AM
To:  <dot...@li...>
Cc:  Jasmine Jha <jha...@gm...>, mital kapadia
<kap...@gm...>
Subject:  [dotNetRDF-Support] sparql query with prefix doesnot work in
dotnetrdf but without prefix works plz help

> 
> 
> my main function says--
> 
> static void Main(string[] args)
>         {
> 
>             Graph g = new Graph();
>             FileLoader.Load(g, "\\cbcs.owl <file://\\cbcs.owl> ");
> 
>             
>             TripleStore store = new TripleStore();
>             store.Add(g);
>             //Object results = store.ExecuteQuery("SELECT * WHERE { { ?s ?p ?o
> } UNION { GRAPH ?g { ?s ?p ?o } } }");
> 
>             Object results = store.ExecuteQuery("PREFIX
> pre:<http://www.cbcs.com/ontologies/cbcs.owl#>" + "SELECT ?X ?Y WHERE { ?X
> pre:hasInstitutes ?Y .}");
>             SparqlResultSet rset = (SparqlResultSet)results;
> 
>             //Enumerating via the Results property
>             foreach (SparqlResult result in rset.Results)
>             {
>                 Console.WriteLine(result.ToString());
>             }
> 
> 
>             Console.WriteLine("hello");
>             Console.ReadLine();
>         }
> 
> 
> but it doesnt display the answer if my query is simple and without answer it
> works but with prefix it doesnt please help
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[dotNetRDF-Support] sparql query with prefix doesnot work in dotnetrdf but without prefix works plz help

[Jasmine S. <jas...@gm...>]

my main function says--

static void Main(string[] args)
        {

            Graph g = new Graph();
            FileLoader.Load(g, "\\cbcs.owl");


            TripleStore store = new TripleStore();
            store.Add(g);
            //Object results = store.ExecuteQuery("SELECT * WHERE { { ?s ?p
?o } UNION { GRAPH ?g { ?s ?p ?o } } }");

            Object results = store.ExecuteQuery("PREFIX pre:<
http://www.cbcs.com/ontologies/cbcs.owl#>" + "SELECT ?X ?Y WHERE { ?X
pre:hasInstitutes ?Y .}");
            SparqlResultSet rset = (SparqlResultSet)results;

            //Enumerating via the Results property
            foreach (SparqlResult result in rset.Results)
            {
                Console.WriteLine(result.ToString());
            }


            Console.WriteLine("hello");
            Console.ReadLine();
        }


but it doesnt display the answer if my query is simple and without answer
it works but with prefix it doesnt please help

Re: [dotNetRDF-Support] Bug in VDS.RDF.Graph.Retract(IEnumerable<Triple> ts)?

[Yossi C. <yos...@li...>]

Understood,Thanks.

Date: Tue, 29 Jan 2013 10:09:49 +0000
From: rv...@do...
To: dot...@li...
Subject: Re: [dotNetRDF-Support] Bug in VDS.RDF.Graph.Retract(IEnumerable<Triple> ts)?

Hi Yossi
This behavior is by design, we don't explicitly materialize the enumerable that comes in because we don't know (or want to know) where it came from and we don't want to waste memory materializing the list unnecessarily.
If you are retracting some enumerable of triples returned by one of the other methods of the graph you are trying to retract from then you need to ensure you materialize that list by calling ToList() on the enumerable you pass in.
Rob
From:  Yossi Cohen <yos...@li...>
Reply-To:  dotNetRDF User Help and Support <dot...@li...>
Date:  Tuesday, January 29, 2013 8:37 AM
To:  DotNetRDF mailing-list <dot...@li...>
Subject:  [dotNetRDF-Support] Bug in VDS.RDF.Graph.Retract(IEnumerable<Triple> ts)?

I think there is a bug in Graph.cs:
public override bool Retract ( IEnumerable<Triple> ts){    bool retracted = false;
    foreach (Triple t in ts)    {        retracted = this.Retract(t) || retraced;    }
    return retracted;}
The 'ts' collectionis modified while enumerated. 		 	   		  ------------------------------------------------------------------------------
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Re: [dotNetRDF-Support] Bug in VDS.RDF.Graph.Retract(IEnumerable<Triple> ts)?

[Rob V. <rv...@do...>]

Hi Yossi

This behavior is by design, we don't explicitly materialize the enumerable
that comes in because we don't know (or want to know) where it came from and
we don't want to waste memory materializing the list unnecessarily.

If you are retracting some enumerable of triples returned by one of the
other methods of the graph you are trying to retract from then you need to
ensure you materialize that list by calling ToList() on the enumerable you
pass in.

Rob

From:  Yossi Cohen <yos...@li...>
Reply-To:  dotNetRDF User Help and Support
<dot...@li...>
Date:  Tuesday, January 29, 2013 8:37 AM
To:  DotNetRDF mailing-list <dot...@li...>
Subject:  [dotNetRDF-Support] Bug in
VDS.RDF.Graph.Retract(IEnumerable<Triple> ts)?

> I think there is a bug in Graph.cs:
> 
> public override bool Retract ( IEnumerable<Triple> ts)
> {
>     bool retracted = false;
> 
>     foreach (Triple t in ts)
>     {
>         retracted = this.Retract(t) || retraced;
>     }
> 
>     return retracted;
> }
> 
> The 'ts' collectionis modified while enumerated.
> ------------------------------------------------------------------------------
> Master Visual Studio, SharePoint, SQL, ASP.NET, C# 2012, HTML5, CSS, MVC,
> Windows 8 Apps, JavaScript and much more. Keep your skills current with
> LearnDevNow - 3,200 step-by-step video tutorials by Microsoft MVPs and
> experts. ON SALE this month only -- learn more at:
> http://p.sf.net/sfu/learnnow-d2d______________________________________________
> _ dotNetRDF-Support mailing list dot...@li...
> https://lists.sourceforge.net/lists/listinfo/dotnetrdf-support

[dotNetRDF-Support] Bug in VDS.RDF.Graph.Retract(IEnumerable<Triple> ts)?

[Yossi C. <yos...@li...>]

I think there is a bug in Graph.cs:
public override bool Retract ( IEnumerable<Triple> ts){    bool retracted = false;
    foreach (Triple t in ts)    {        retracted = this.Retract(t) || retraced;    }
    return retracted;}
The 'ts' collectionis modified while enumerated. 		 	   		  

Re: [dotNetRDF-Support] Ontology printer output like Protege

[Rob V. <rv...@do...>]

Hi Rene

dotNetRDF comes with a variety of writers that can be used to write graphs
back out to files, see the Writing RDF [1] documentation for an overview.
See the IRdfWriter documentation [2] for a list of available
implementations.

For your specific question I suspect you likely want to use the
CompressingTurtleWriter [3], I don't know exactly what the Protégé Turtle
export looks like but this writer should give you fairly nice and compact
Turtle.  You may want to turn up the compression level to get the best out
of this.

Hope this helps,

Rob

[1] http://www.dotnetrdf.org/content.asp?pageID=Writing%20RDF
[2] http://www.dotnetrdf.org/api/index.asp?Topic=VDS.RDF.IRdfWriter
[3] 
http://www.dotnetrdf.org/api/index.asp?Topic=VDS.RDF.Writing.CompressingTurt
leWriter

From:  Raynier van Egmond <ra...@xb...>
Organization:  XBRL Consulting Partners LLC
Reply-To:  <ra...@xb...>, dotNetRDF User Help and Support
<dot...@li...>
Date:  Wednesday, January 23, 2013 9:47 PM
To:  <dot...@li...>
Subject:  [dotNetRDF-Support] Ontology printer output like Protege

> Hi All,
>  
> I have started using dotNetRDF for a prototype ontology server and wondered if
> there is a ³writer-class² that formats the output of the content of a graph
> like the turtle export from Protégé? Since I use both (Protégé to confirm that
> my manual modeling is done correctly) it would be very helpful to be able to
> round-trip the two files (into and  out-of Protégé and the dotNetRDF
> application).
>  
> If there is no such thing (yet) would I need to create my own formatter to
> achieve this? Which wouldn¹t be a problem but if it¹s not neededŠ
>  
> Kind regards,
>  
> 
> René
> Vashon (WA), USA
> ------------------------------------------------------------------------------
> Master Visual Studio, SharePoint, SQL, ASP.NET, C# 2012, HTML5, CSS, MVC,
> Windows 8 Apps, JavaScript and much more. Keep your skills current with
> LearnDevNow - 3,200 step-by-step video tutorials by Microsoft MVPs and
> experts. ON SALE this month only -- learn more at:
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> https://lists.sourceforge.net/lists/listinfo/dotnetrdf-support

[dotNetRDF-Support] Ontology printer output like Protege

[Raynier v. E. <ra...@xb...>]

Hi All,

 

I have started using dotNetRDF for a prototype ontology server and wondered
if there is a “writer-class” that formats the output of the content of a
graph like the turtle export from Protégé? Since I use both (Protégé to
confirm that my manual modeling is done correctly) it would be very helpful
to be able to round-trip the two files (into and  out-of Protégé and the
dotNetRDF application).

 

If there is no such thing (yet) would I need to create my own formatter to
achieve this? Which wouldn’t be a problem but if it’s not needed…

 

Kind regards,

 

René

Vashon (WA), USA

Re: [dotNetRDF-Support] parsing RDF

[Rob V. <rv...@do...>]

Hey Ryan

What exactly do you want to do here?  You can easily parse this RDF/XML as
triples into dotNetRDF like so:

Graph g = new Graph();
g.LoadFromFile("your-file.rdf");

And then you can find the expression string either with a SPARQL query or
using the Graph API to select the relevant pieces of data e.g.

IEnumerable<ILiteralNode> ns =
g.GetTriplesWithPredicate(g.CreateUriNode("kb:expression_string")).Select(t
=> t.Object).OfType<ILiteralNode>();
foreach (ILiteralNode n in ns)
{
  //The variable n holds the literal representing your let expression
  //Access it's value like so
  String exprStr = n.Value;

  //Do something with the expression stringŠ
}

However there is no support for parsing these let expressions, I assume
these are some sort of Protégé specific feature?  You can easily access this
data as I demonstrated but I'm afraid you would be on your own for parsing
it and interpreting it.

If you have more specific questions we may be able to provide you with more
specific answers,

Regards,

Rob

From:  Ryan Minor <mi...@ya...>
Reply-To:  Ryan Minor <mi...@ya...>, dotNetRDF User Help and Support
<dot...@li...>
Date:  Wednesday, January 23, 2013 12:07 AM
To:  "dot...@li..."
<dot...@li...>
Subject:  [dotNetRDF-Support] parsing RDF

> Hi there
> 
> I am new to RDF.  I am trying to use dotnetrdf to parse a file creating using
> Protege (Stanford).
> 
> The following is an excerpt from my file:
> 
> <?xml version='1.0' encoding='UTF-8'?>
> <!DOCTYPE rdf:RDF [
>  <!ENTITY rdf 'http://www.w3.org/1999/02/22-rdf-syntax-ns#'>
>  <!ENTITY a 'http://protege.stanford.edu/system#'>
>  <!ENTITY kb 'http://protege.stanford.edu/kb#'>
>  <!ENTITY rdfs 'http://www.w3.org/2000/01/rdf-schema#'>
> ]>
> 
> <rdf:RDF xmlns:rdf="&rdf;"
>  xmlns:a="&a;"
>  xmlns:kb="&kb;"
>  xmlns:rdfs="&rdfs;">
> 
> <kb:Let_Expression rdf:about="&kb;CoughStudy3_00730"
>  kb:identifier="coughStartTime"
>  kb:name="Current cough start time"
>  rdfs:label="Current cough start time">
> <kb:expression_string>selectAttribute("low", selectAttribute("critical_time",
> selectAttribute("value", latest cough where time of it >=
> now)))</kb:expression_string>
> </kb:Let_Expression>
> 
> 
> The last paragraph is describing something called a Let_Expression.
> 
> Any suggestions on parsing this in dotnetrdf?
> 
> 
> ------------------------------------------------------------------------------
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[dotNetRDF-Support] parsing RDF

[Ryan M. <mi...@ya...>]

Hi there

I am new to RDF.  I am trying to use dotnetrdf to parse a file creating using Protege (Stanford).

The following is an excerpt from my file:

<?xml version='1.0' encoding='UTF-8'?>
<!DOCTYPE rdf:RDF [
 <!ENTITY rdf 'http://www.w3.org/1999/02/22-rdf-syntax-ns#'>
 <!ENTITY a 'http://protege.stanford.edu/system#'>
 <!ENTITY kb 'http://protege.stanford.edu/kb#'>
 <!ENTITY rdfs 'http://www.w3.org/2000/01/rdf-schema#'>
]>

<rdf:RDF xmlns:rdf="&rdf;"
 xmlns:a="&a;"
 xmlns:kb="&kb;"
 xmlns:rdfs="&rdfs;">

<kb:Let_Expression rdf:about="&kb;CoughStudy3_00730"
 kb:identifier="coughStartTime"
 kb:name="Current cough start time"
 rdfs:label="Current cough start time">
<kb:expression_string>selectAttribute("low", selectAttribute("critical_time", selectAttribute("value", latest cough where time of it >= now)))</kb:expression_string>
</kb:Let_Expression>


The last paragraph is describing something called a Let_Expression.

Any suggestions on parsing this in dotnetrdf? 

Re: [dotNetRDF-Support] Adding Context to Triples

[Yossi C. <yos...@li...>]

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