DBPedia (de) data with JENA: character encoding errors ("not unicode")

I try to acces DBpedia (de) data on my local machine. Having downloaded and unzipped some ttl-Files I tried to test a very simple SPARQL query.

PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> 
PREFIX skos: <http://www.w3.org/2004/02/skos/core#>
PREFIX rdfs:  <http://www.w3.org/2000/01/rdf-schema#>

SELECT DISTINCT ?s 
WHERE
{
 ?s rdf:type skos:Concept .
 ?s rdfs:label ?label .
}
LIMIT 100

using this ARQ command (on Windows):

arq --data dewiki-20140813-article-categories.ttl --query dbpedia_cat.rq

I did expect that nothing could go wrong, but instead, I got a bunch of errors like these:

19:29:02 WARN  riot                 :: [line: 2860693, col: 1 ] Bad IRI: <http:/
/de.dbpedia.org/resource/à_Baby_One_More_Time> Code: 47/NOT_NFKC in PATH: The IR
I is not in Unicode Normal Form KC.
19:29:02 WARN  riot                 :: [line: 2860693, col: 1 ] Bad IRI: <http:/
/de.dbpedia.org/resource/à_Baby_One_More_Time> Code: 56/COMPATIBILITY_CHARACTER
in PATH: TODO
19:29:02 WARN  riot                 :: [line: 2860694, col: 1 ] Bad IRI: <http:/
/de.dbpedia.org/resource/à_Baby_One_More_Time> Code: 47/NOT_NFKC in PATH: The IR
I is not in Unicode Normal Form KC.
19:29:02 WARN  riot                 :: [line: 2860694, col: 1 ] Bad IRI: <http:/
/de.dbpedia.org/resource/à_Baby_One_More_Time> Code: 56/COMPATIBILITY_CHARACTER
in PATH: TODO

After those errors, ARQ added the following:

Exception in thread "main" java.lang.OutOfMemoryError: GC overhead limit exceede
d
        at org.apache.jena.riot.tokens.TokenizerText.parseToken(TokenizerText.ja
va:170)
        at org.apache.jena.riot.tokens.TokenizerText.hasNext(TokenizerText.java:
86)
        at org.apache.jena.atlas.iterator.PeekIterator.fill(PeekIterator.java:50
)
        at org.apache.jena.atlas.iterator.PeekIterator.next(PeekIterator.java:92
)
        at org.apache.jena.riot.lang.LangEngine.nextToken(LangEngine.java:99)
        at org.apache.jena.riot.lang.LangTurtleBase.predicateObjectItem(LangTurt
leBase.java:287)
        at org.apache.jena.riot.lang.LangTurtleBase.predicateObjectList(LangTurt
leBase.java:269)
        at org.apache.jena.riot.lang.LangTurtleBase.triples(LangTurtleBase.java:
250)
        at org.apache.jena.riot.lang.LangTurtleBase.triplesSameSubject(LangTurtl
eBase.java:191)
        at org.apache.jena.riot.lang.LangTurtle.oneTopLevelElement(LangTurtle.ja
va:44)
        at org.apache.jena.riot.lang.LangTurtleBase.runParser(LangTurtleBase.jav
a:90)
        at org.apache.jena.riot.lang.LangBase.parse(LangBase.java:42)
        at org.apache.jena.riot.RDFParserRegistry$ReaderRIOTLang.read(RDFParserR
egistry.java:182)
        at org.apache.jena.riot.RDFDataMgr.process(RDFDataMgr.java:906)
        at org.apache.jena.riot.RDFDataMgr.parse(RDFDataMgr.java:687)
        at org.apache.jena.riot.RDFDataMgr.read(RDFDataMgr.java:534)
        at org.apache.jena.riot.RDFDataMgr.read(RDFDataMgr.java:501)
        at org.apache.jena.riot.RDFDataMgr.read(RDFDataMgr.java:454)
        at org.apache.jena.riot.RDFDataMgr.read(RDFDataMgr.java:432)
        at org.apache.jena.riot.RDFDataMgr.read(RDFDataMgr.java:422)
        at arq.cmdline.ModDatasetGeneral.addGraphs(ModDatasetGeneral.java:101)
        at arq.cmdline.ModDatasetGeneral.createDataset(ModDatasetGeneral.java:90
)
        at arq.cmdline.ModDatasetGeneralAssembler.createDataset(ModDatasetGenera
lAssembler.java:35)
        at arq.cmdline.ModDataset.getDataset(ModDataset.java:34)
        at arq.query.getDataset(query.java:176)
        at arq.query.queryExec(query.java:198)
        at arq.query.exec(query.java:159)
        at arq.cmdline.CmdMain.mainMethod(CmdMain.java:102)
        at arq.cmdline.CmdMain.mainRun(CmdMain.java:63)
        at arq.cmdline.CmdMain.mainRun(CmdMain.java:50)
        at arq.arq.main(arq.java:28)

Having tested two unpacking utilities (Ark on Linux and Winrar on Windows), I'm quite sure that unzipping is not the problem here.

Also I have look at the ttl-Files with Notepad++ and all characters seem right to me, even the problematic ones like Ä,Ö, Ü etc.

So, I have no idea how to cope with those errors and would appreciate any help!

(Apologizes for asking a question which is not 100% programming related. But I don't know whether JENA or DBPedia is the problem here and thus, which mailing list would be appropriate. However, it is a beginner's question anyway. So, I hope someone here could help.)

Solution

The WARN are just that warnings - not errors. The data is encoded into UTF-8 in a way that is not preferred by W3C standards.

This

--data dewiki-20140813-article-categories.ttl

loads all the data into memory, hence you run out of space. Either load into a database like TDB or if the file looks like it might fir in memory on your machine, increase the heap size.