June 2013 - BaseX-Talk - mailman.uni-konstanz.de

Out of Main Memory; bytea type
by Alexander von Bernuth 24 Jun '13

24 Jun '13

Hello all, my basex-script should fetch 10.000something XML-files automatically from a website and insert their content into a external PostgreSQL-database. After about 8.000 files my script stops and I get "Out of Main Memory". I found your discussion with "kgfhjjgrn" [1] regarding this issue, but I'm not sure whether these options apply to my problem - I do not build a basex-database but an external one. Will autoflush=false and flushing by myself help with this? Second, I want to insert some xs:base64Binary into my PostgreSQL database, but I cannot find the correct sql:parameter type for the bytea-column. Could you please help me with my issues? Thank you very much, Alexander [1] http://comments.gmane.org/gmane.text.xml.basex.talk/2540 -- | Alexander von Bernuth | alexander.von-bernuth(a)student.uni-tuebingen.de

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BaseX and XML 1.0/1.1 names (and other implementation-defined items)
by C. M. Sperberg-McQueen 24 Jun '13

24 Jun '13

For reasons I won't go into here, I have developed a desire to know something I've never particularly wondered about in the past: Which version of XML NCNames does BaseX use? The one given in XML 1.0 5th edition and in XML 1.1? or the one given in earlier versions of XML? And while I'm looking for implementation-defined properties -- is there a place in the documentation that lists BaseX's decisions on the various implementation-defined items listed in http://www.w3.org/TR/xpath20/#id-impl-defined-items and http://www.w3.org/TR/xquery/#id-impl-defined-items ? I did a search in the documentation for "implementation-defined" but did not find any likely candidates among the hits; I may have overlooked it, though. -- **************************************************************** * C. M. Sperberg-McQueen, Black Mesa Technologies LLC * http://www.blackmesatech.com * http://cmsmcq.com/mib * http://balisage.net ****************************************************************

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Error messages from BaseX.main()
by Brock, David 19 Jun '13

19 Jun '13

I want to call BaseX.main() from a Java GUI and need to display errors to the user. There are no exceptions thrown by this method, and I do not see a way to redirect so that I can capture and display. Thanks, David

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Best practices for concurrency
by The Trainspotter 19 Jun '13

19 Jun '13

Hi, I've read through the online example on server concurrency, however, currently I'm not running a BaseXServer instance I'm just running things locally. I want multiple threads in my application to be able to query the database at once without treading on each others toes. What's the best approach for doing this? I have tried querying the database using different threads but I keep getting internal BaseX errors which leads me to think I'm going about this the wrong way. Cheers Gary

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basex client can't connect: Can't communicate with the server.
by Paul Collins 18 Jun '13

18 Jun '13

Hi, I use basex on Debian wheezy with Oracle Java version 1.6.0_43. Whenever I try to connect to the basex server the client tells me "Can't communicate with the server." If I enable a netcat server on port 2000 for test reasons and run wireshark in order to capture the traffic I get no traffic on port 2000, not even the TCP three way handshake by running this command: java -cp BaseX77.jar org.basex.BaseXClient -p2000 -n localhost -d Do you have any suggestions why as far as I can see the basex client doesn't even try to connect to port 2000 on localhost but just prints that it can't communicate with the server? Best regards, Paul

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bug in processing XPATH with this simple regular expression?
by Imbuter Imb 17 Jun '13

17 Jun '13

Take this input: <div id="ps-content">foobar</div> and apply this XPATH 2+: //div[matches(@id,"^s-content$")] In BaseX command-line it matched! despite the fact that "^" in regex language means "the start of the string". With Saxon and Xidel command-line it correctly doesn't match. Why does it match in BaseX?

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An inconvenient truth . . ?
by Christopher.R.Ball 15 Jun '13

15 Jun '13

Am I correct in assuming I have hit a dreaded limit of BaseX when I see the output below? Which I presume may be the node limit (2,147,483,648) . . ? As I am dealing with 689,701 Files in 814,855 Folders which amounts to 5.32 GB on disk. (I am running BaseX 7.7) If so, then are then any automated ways of having BaseX automatically start feeding to a second instance? It would be nice to NOT have to manually partition the content in advance. Thoughts? ..................................;...................................;...............................;................. .......;.......;......;.......;.............;.................org.basex.build.BuildException: "825646564637.xml" (Line 3 5100): Input is too large for a single database. at org.basex.build.Builder.limit(Builder.java:327) at org.basex.build.Builder.addElem(Builder.java:315) at org.basex.build.Builder.openElem(Builder.java:111) at org.basex.build.xml.XMLParser.parseTag(XMLParser.java:176) at org.basex.build.xml.XMLParser.parse(XMLParser.java:88) at org.basex.build.SingleParser.parse(SingleParser.java:33) at org.basex.build.DirParser.parseResource(DirParser.java:180) at org.basex.build.DirParser.parse(DirParser.java:110) at org.basex.build.DirParser.parse(DirParser.java:90) at org.basex.build.DirParser.parse(DirParser.java:90) at org.basex.build.DirParser.parse(DirParser.java:90) at org.basex.build.DirParser.parse(DirParser.java:90) at org.basex.build.DirParser.parse(DirParser.java:90) at org.basex.build.DirParser.parse(DirParser.java:79) at org.basex.build.Builder.parse(Builder.java:73) at org.basex.build.DiskBuilder.build(DiskBuilder.java:90) at org.basex.build.DiskBuilder.build(DiskBuilder.java:1) at org.basex.core.cmd.Add.run(Add.java:103) at org.basex.core.Command.run(Command.java:345) at org.basex.core.Command.exec(Command.java:321) at org.basex.core.Command.execute(Command.java:78) at org.basex.server.LocalSession.execute(LocalSession.java:122) at org.basex.server.Session.execute(Session.java:37) at org.basex.core.Main.execute(Main.java:146) at org.basex.core.Main.execute(Main.java:130) at org.basex.core.Main.execute(Main.java:117) at org.basex.BaseX.<init>(BaseX.java:79) at org.basex.BaseX.main(BaseX.java:39)

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Doubtful question on xquery:eval ...
by Marco Lettere 14 Jun '13

14 Jun '13

Hello all, I just would like to know if this wanted or not ... When I run the following query in the GUI with all databases closed for $rvs at $pos in collection('examples/valuesets/resolved') return $rvs it returns the correct dataset. The same query put into an xquery:eval xquery:eval("for $rvs at $pos in collection('examples/valuesets/resolved') return $rvs") gives a result if the database "examples" has been opened. With no open database I get an error message "Improper use or potential bug ...." and the console the GUI is running in return the following stacktrace: java.io.IOException: Stream Closed java.io.RandomAccessFile.seek(Native Method) org.basex.io.random.DataAccess.cursor(DataAccess.java:229) org.basex.io.random.DataAccess.readToken(DataAccess.java:168) org.basex.data.DiskData.txt(DiskData.java:267) org.basex.data.DiskData.text(DiskData.java:235) org.basex.io.serial.Serializer.node(Serializer.java:389) org.basex.io.serial.Serializer.serialize(Serializer.java:99) org.basex.io.serial.Serializer.serialize(Serializer.java:84) org.basex.query.iter.ValueBuilder.serialize(ValueBuilder.java:80) org.basex.query.iter.ValueBuilder.serialize(ValueBuilder.java:75) org.basex.core.cmd.AQuery.query(AQuery.java:80) org.basex.core.cmd.XQuery.run(XQuery.java:22) org.basex.core.Command.run(Command.java:342) org.basex.core.Command.exec(Command.java:321) org.basex.core.Command.execute(Command.java:78) org.basex.gui.GUI.exec(GUI.java:397) org.basex.gui.GUI$7.run(GUI.java:349)

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XQuery to insert nodes in XML File
by John Best 14 Jun '13

14 Jun '13

Dear Team, I am trying to insert few nodes in a XML File. But in reality the nodes are not inserting in the XML File!! Below is my query for $x in doc('C:\sample.xml')//CInfos return insert node <Info><Name>James Stuart</Name><Key>7709422869</Key></Info> as last into $x I tried with another query - insert node <Info> <Name>James Stuart</Name> <Key>7709422869</Key> </Info> as last into doc('C:\sample.xml')//CInfos This too not working If I create a XML DB and then it works... What am I missing? -- Have a nice day JBest

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Re: [basex-talk] Java DOM Interface and updating XQueries
by Ingo Dengler 13 Jun '13

13 Jun '13

Hi Christian, the problem also exists with DBNode, isn't it? DBNode internally stores the pre of the node at time of instantiation of the object. After an update of DB the internally stored pre points to a wrong node. Of course one could use the ID of DBNode and use db:open-id(id) to get a new DBNode with correct pre. But this approach doesn't work with DOM API. My question is, is there a possible solution that allows me to use DOM interface (We need DOM, because we want to use BaseX to replace an old DOM based parser class without reimplementing everything) and updating expressions? Best regards, Ingo > Hi Ingo, > > as you correctly observed, we are using 'pre' values to organize nodes > in our database, which will change after updates (see [1] for further > details on pre and id values and the id/pre mapping). It is generally > possible to use our DOM interface, but I’m inclined to recommend you > the database functions db:open-pre() and db:node-pre(). If you perform > updates, db:open-id() and db:node-id() and the UPDINDEX option will > help you [2]. You could also work with the DBNode instances, which are > returned by the query processor, as this will be much faster than > using the DOM wrapper, but it may take more time to get acquainted > with the internal node interface. > > Regards, > Christian > > [1] http://docs.basex.org/wiki/Node_Storage#PRE_Value > [2] http://docs.basex.org/wiki/Database_Module#db:open-pre[http://docs.basex.or…

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