July 2012 - BaseX-Talk - mailman.uni-konstanz.de

usability issue in GUI
by Godmar Back 11 Jul '12

11 Jul '12

Hi, is it possible to connect the GUI to an existing server? If not, I think it really should be, rather than requiring than the GUI start the server. - Godmar

2 3

improve BaseX error message
by Godmar Back 10 Jul '12

10 Jul '12

It should be "outdated" or "out-of-date", not "out-of-dated". Looks like moving to 7.3 is a bigger effort than thought... - Godmar java.io.IOException: Protocol for query iteration is out-of-dated. at org.libx.support.basex.BaseXSessionSupport$Query.exec(BaseXSessionSupport.java:324) at org.libx.support.basex.BaseXSessionSupport$Query.more(BaseXSessionSupport.java:270) at org.libx.support.basex.BaseXSession$1.next(BaseXSession.java:104) at org.libx.support.basex.XMLDatabaseClient$1.after(XMLDatabaseClient.java:53) at org.libx.support.basex.BaseXSession.runQuery(BaseXSession.java:100) at org.libx.support.basex.XMLDatabaseClient.runQuery(XMLDatabaseClient.java:40) at org.libx.support.basex.XMLDatabaseClient.runQueryAsString(XMLDatabaseClient.java:95) at org.libx.support.basex.XMLDatabaseOperation$2.run(XMLDatabaseOperation.java:65) at org.libx.support.basex.XMLDatabaseOperation$2.run(XMLDatabaseOperation.java:62) at org.libx.support.basex.XMLDatabaseOperation.execute(XMLDatabaseOperation.java:46) at org.libx.support.basex.XMLDatabaseOperation.runQueryAsString(XMLDatabaseOperation.java:62)

2 2

problem using BaseX GUI
by Godmar Back 10 Jul '12

10 Jul '12

I'm using the most recent BaseX GUI; I'm trying to change the value of an attribute in an XML document. This results in the following exception: java.lang.ArrayIndexOutOfBoundsException: -1 org.basex.util.list.IntList.get(IntList.java:65) org.basex.gui.view.info.InfoView.setInfo(InfoView.java:173) org.basex.gui.GUI.exec(GUI.java:402) org.basex.gui.GUI$6.run(GUI.java:343) (see attached screenshot). I can't provide a reproducible test case; my second attempt to change the attribute value succeeded, see log below, but perhaps this backtrace helps the developers fix this issue. - Godmar // log of successful execution upon second attempt Query: replace value of node db:open-pre("feed_libx_dot_editions_at_gmail_dot_com_core", 827) with "161" Compiling: - pre-evaluating db:open-pre("feed_libx_dot_editions_at_gmail_dot_com_core", 827) Result: replace value of node attribute src { " libx.editions(a)gmail.com/core/161" } with "161" Timing: - Parsing: 0.66 ms - Compiling: 0.22 ms - Evaluating: 3.29 ms - Printing: 0.06 ms - Total Time: 4.25 ms Result: - Hit(s): 0 Items - Updated: 1 Item - Printed: 0 Bytes Query plan: <QueryPlan> <Replace> <DBNode name="feed_libx_dot_editions_at_gmail_dot_com_core" pre="827"/> <Str value="161" type="xs:string"/> </Replace> </QueryPlan>

2 1

Replication with BaseX
by Usama Dar 10 Jul '12

10 Jul '12

Hi Guys, I am new to BaseX and i am going to use it to store 500K XML documents which will be edited, Queried and stuff. I have already built the main application. I have need to be able to run BaseX in a high availability environment. For that i will initially have two servers and i plan to use rsync on baseX data directory to replicate data. My question basically is are there any recommended strategies to do this? is using rsync going to do the job? i can copy files over in the data directory in a running instance? or the other server should be shutdown while i copy files? any tool/ strategy you might know of? Thanks for your help Usama Dar.

1 0

Performance of Add command
by Manuel Bernhardt 10 Jul '12

10 Jul '12

Hi, I'm doing some testing before migration one of our customers to a new version of our platform that uses BaseX in order to store documents. They have approx. 4M documents, and I'm running an import operation on a 1 M document collection on my laptop. The way I'm inserting documents is by firing off one Add command per document, based on a stream of the document, at a different (unique) path for each document, and flushing every at 10K Adds. Since most CPU usage (for one of the cores, the other ones being untouched) is taken by the BaseX server, I fired up YourKit out of curiosity to see where the CPU time was spent. My machine is a 2*4 core MacBook Pro with 8GB of RAM and SSD, so I think hardware-wise it should do pretty fine. YourKit shows that what seems to use up most time is the Namespaces.update method: Thread-12 [RUNNABLE] CPU time: 2h 7m 9s org.basex.data.Namespaces.update(NSNode, int, int, boolean, Set) org.basex.data.Namespaces.update(int, int, boolean, Set) org.basex.data.Data.insert(int, int, Data) org.basex.core.cmd.Add.run() org.basex.core.Command.run(Context, OutputStream) org.basex.core.Command.exec(Context, OutputStream) org.basex.core.Command.execute(Context, OutputStream) org.basex.core.Command.execute(Context) org.basex.server.ClientListener.execute(Command) org.basex.server.ClientListener.add() org.basex.server.ClientListener.run() I'm not really sure what that method does - it's a recursive function and seems to be triggered by Data.insert: // NSNodes have to be checked for pre value shifts after insert nspaces.update(ipre, dsize, true, newNodes); The whole set of records should have no more than 5 different namespaces in total. Thus I'm wondering if there would perhaps be some potential for optimization here? Note that I'm completely ignorant as to what the method does and what its exact purpose is. Thanks, Manuel PS: the import is now finished: Storing 1001712 records into BaseX took 9285008 ms

2 11

Incorrect use of timezone Z instead of implicit timezone
by Gunther Rademacher 09 Jul '12

09 Jul '12

As explained in http://www.w3.org/TR/xquery-operators/#func-subtract-dates the implicit timezone should be used for augmenting an xs:date without a timezone before subtracting it from one with a timezone. BaseX however appears to be using timezone Z in this case. The following xquery demonstrates this: current-date() - xs:date(substring(string(current-date()), 1, 10)) It should return a zero duration, but BaseX returns -PT2H I am in timezone +02:00. Best regards Gunther

2 1

FW: Problem with RunQueries.java example!!
by Anand Chiney (AIR) 09 Jul '12

09 Jul '12

Dear BaseX Team, The below code is working fine and I am getting the required output - for $x in doc('input.xml')//li return $x/text() i.e; ------------------------Output with XML File---------------- Example 1 Example 2 Example 3 ------------------------------------------------------------ But when I try the same with BaseX DB , I am not getting the required output ;-( for $x in doc('input')//li return $x/text() ------------------------Output with DB---------------------- Example 1Example 2Example 3 ------------------------------------------------------------ Now the first output can easily be populated in the Combo box, but what about the second..? The length of the output is not fixed in real application... I have attached the input.xml file. Regards, Anand Chiney -----Original Message----- From: Christian Grün [mailto:christian.gruen@gmail.com] Sent: Saturday, July 07, 2012 5:42 PM To: Anand Chiney (AIR); BaseX Subject: Re: Problem with RunQueries.java example!! Dear Anand, > Thanks for the reply. The serialize() did work. But what I was expecting > Is pure textual output and I am getting XML output. The output which I am > getting is - I strongly recommend you to spend some more time to get into XPath and XQuery, as those issues can all be realized fairly easily with the languages themselves. Some straightforward tutorials are e.g. found at [1,2]. Here are some examples (among many others) how you could rewrite your query to get the desired results: for $x in doc('input.xml')//li return $x/text() doc('input.xml')//li/text() doc('input.xml')//li/string() doc('input.xml')//li/data() You can also compose the whole combobox within XQuery. Your query could then look like <select>{ for $x in doc('input.xml')//li return <option>{ $x/text() }</option> }</select> or element select { doc('input.xml')//li ! element option { text() } } Hope this helps, Christian [1] http://www.w3schools.com/xpath [2] http://www.w3schools.com/xquery > > ----------------------------------------------------------- > * Convert each result to its Java representation: > Iterator > <li>Exercise 1</li> > <li>Exercise 2</li> > ----------------------------------------------------------- > > But I am expecting this is - > > Exercise 1 > Exercise 2 > > Actually I want to populate a JComboBox which is a part of my front-end. > So I thought that this piece of code, where it is said "Java > representation", would gimme the output as I required. > > Can you help me a little more..? > Which method will gimme the plain output, without the XML Tags...? So that > I can populate a JComboBox... !! > > > Regards, > Anand Chiney > > > -----Original Message----- > From: Christian Grün [mailto:christian.gruen@gmail.com] > Sent: Saturday, July 07, 2012 5:02 PM > To: Anand Chiney (AIR); BaseX > Subject: Re: Problem with RunQueries.java example!! > > Here's a second feedback (sorry for being distracted): Your query does > return standard Java DOM elements, the toString() method of which > returns "[li: null]". As you are probably interested in the string > representation of the elements, you'll need to replace "toJava()" with > "serialize()": > > System.out.println(item.serialize()); > > Hope this helps, > Christian > ___________________________ > > On Sat, Jul 7, 2012 at 1:26 PM, Christian Grün > <christian.gruen(a)gmail.com> wrote: >> Your query will yield the expected results if you remove the explicit >> cq.execute(); call. >> >> In the latest snapshot [1], an exception will be returned if the >> result has already been requested. >> >> Hope this helps, >> Christian >> >> [1] http://files.basex.org/releases/latest/ >> ___________________________ >> >>> Dear Christian >>> >>> Please find attached 2 files, MyRunQueries.java and input.xml >>> >>> The .java file is an edited version of RunQueries.java version and the >>> >>> I hope this would be sufficient for you to test. >>> >>> >>> >>> Regards >>> Anand chiney >>> >>> -----Original Message----- >>> From: Christian Grün [mailto:christian.gruen@gmail.com] >>> Sent: Saturday, July 07, 2012 4:34 PM >>> To: Sandeep Yohans >>> Cc: Anand Chiney; basex-talk(a)mailman.uni-konstanz.de >>> Subject: Re: Problem with RunQueries.java example!! >>> >>> One again I'm sorry Please send us a (small !) example that we can >>> try by ourselves. >>> >>> Thank you in advance, >>> Christian >>> ___________________________ >>> >>> On Sat, Jul 7, 2012 at 1:02 PM, Sandeep Yohans <sandeepy.air(a)gmail.com> >>> wrote: >>>> Hello Christian, >>>> >>>> We are extracting names from a very long list of names. The > item.toJava() >>>> method call in iterate(query) is returning null. >>>> example output: >>>> >>>> [li: null] >>>> >>>> Rest of the methods are printing output fine. >>>> >>>> >>>> -- >>>> Thanks and Regards >>>> >>>> Sandeep Yohans >>>> Software Developer >>>> Systems - AIR Infotech >>>> Nagpur - India >>>> www.airinfotech.in >>>> Mobile: +91-997-086-5520 >>>> >

2 1

BaseX with a Booleen Column
by Scott Clayton 09 Jul '12

09 Jul '12

Hey... I know this may be getting out of the native XML database talk but it would be great if we could add a column and mark as true or false when we grab the data from an external source and mark as gotten. Anyways...just a thought. Maybe there is a plugin for this or something to the effect? Best, Scott PS - I sent a similar email to the default contact at BaseX.org site and after I sent it there was a suggestion to send feature inquiries to this email... I could not find that suggextion until after I had already sent the email. :-)

2 1

BaseX client event protocol
by Andy Bunce 08 Jul '12

08 Jul '12

Hi, I am looking at adding WATCH and UNWATCH to my Node.js BaseX interface and I have a couple of questions before I start. 1) The documentation at http://docs.basex.org/wiki/Server_Protocol shows nothing in the Server Response column. This seems not to be the case. It looks like a standard BaseX protocol type response is to be expected? 2) The example at https://github.com/BaseXdb/basex-examples/blob/master/src/main/java/org/bas… session2 watching and then executing. Does the server protocol identify "event pushes" in some way. That is when I receive a message how can I tell if is a event or a command response? /Andy

2 3

Re: [basex-talk] Problem with RunQueries.java example!!
by Christian Grün 07 Jul '12

07 Jul '12

Dear Anand, > Thanks for the reply. The serialize() did work. But what I was expecting > Is pure textual output and I am getting XML output. The output which I am > getting is - I strongly recommend you to spend some more time to get into XPath and XQuery, as those issues can all be realized fairly easily with the languages themselves. Some straightforward tutorials are e.g. found at [1,2]. Here are some examples (among many others) how you could rewrite your query to get the desired results: for $x in doc('input.xml')//li return $x/text() doc('input.xml')//li/text() doc('input.xml')//li/string() doc('input.xml')//li/data() You can also compose the whole combobox within XQuery. Your query could then look like… <select>{ for $x in doc('input.xml')//li return <option>{ $x/text() }</option> }</select> …or… element select { doc('input.xml')//li ! element option { text() } } Hope this helps, Christian [1] http://www.w3schools.com/xpath [2] http://www.w3schools.com/xquery > > ----------------------------------------------------------- > * Convert each result to its Java representation: > Iterator > <li>Exercise 1</li> > <li>Exercise 2</li> > ----------------------------------------------------------- > > But I am expecting this is - > > Exercise 1 > Exercise 2 > > Actually I want to populate a JComboBox which is a part of my front-end. > So I thought that this piece of code, where it is said "Java > representation", would gimme the output as I required. > > Can you help me a little more..? > Which method will gimme the plain output, without the XML Tags...? So that > I can populate a JComboBox... !! > > > Regards, > Anand Chiney > > > -----Original Message----- > From: Christian Grün [mailto:christian.gruen@gmail.com] > Sent: Saturday, July 07, 2012 5:02 PM > To: Anand Chiney (AIR); BaseX > Subject: Re: Problem with RunQueries.java example!! > > Here's a second feedback (sorry for being distracted): Your query does > return standard Java DOM elements, the toString() method of which > returns "[li: null]". As you are probably interested in the string > representation of the elements, you'll need to replace "toJava()" with > "serialize()": > > System.out.println(item.serialize()); > > Hope this helps, > Christian > ___________________________ > > On Sat, Jul 7, 2012 at 1:26 PM, Christian Grün > <christian.gruen(a)gmail.com> wrote: >> Your query will yield the expected results if you remove the explicit >> cq.execute(); call. >> >> In the latest snapshot [1], an exception will be returned if the >> result has already been requested. >> >> Hope this helps, >> Christian >> >> [1] http://files.basex.org/releases/latest/ >> ___________________________ >> >>> Dear Christian >>> >>> Please find attached 2 files, MyRunQueries.java and input.xml >>> >>> The .java file is an edited version of RunQueries.java version and the >>> >>> I hope this would be sufficient for you to test. >>> >>> >>> >>> Regards >>> Anand chiney >>> >>> -----Original Message----- >>> From: Christian Grün [mailto:christian.gruen@gmail.com] >>> Sent: Saturday, July 07, 2012 4:34 PM >>> To: Sandeep Yohans >>> Cc: Anand Chiney; basex-talk(a)mailman.uni-konstanz.de >>> Subject: Re: Problem with RunQueries.java example!! >>> >>> One again I'm sorry… Please send us a (small !) example that we can >>> try by ourselves. >>> >>> Thank you in advance, >>> Christian >>> ___________________________ >>> >>> On Sat, Jul 7, 2012 at 1:02 PM, Sandeep Yohans <sandeepy.air(a)gmail.com> >>> wrote: >>>> Hello Christian, >>>> >>>> We are extracting names from a very long list of names. The > item.toJava() >>>> method call in iterate(query) is returning null. >>>> example output: >>>> >>>> [li: null] >>>> >>>> Rest of the methods are printing output fine. >>>> >>>> >>>> -- >>>> Thanks and Regards >>>> >>>> Sandeep Yohans >>>> Software Developer >>>> Systems - AIR Infotech >>>> Nagpur - India >>>> www.airinfotech.in >>>> Mobile: +91-997-086-5520 >>>> >

1 0