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

Out of memory bug
by Ivan Lagunov 31 Jul '13

31 Jul '13

Hello, I've got 'Out of memory' error and corrupted database again, this time it's for 6.3 version. Steps: 1. Started server, started terminal client, checked there are no text and attribute indexes. 2. Started my Java application that runs several tests on database: querying, adding, removing. 3. Then I forgot to reopen terminal client and used the one that I opened in Step 1. 4. Run optimize command for the collection and got error. 5. Cannot open the collection any more as I'm getting 'Out of memory'. It's clear that I shouldn't have used the terminal client that I opened before execution of my Java application. But sometimes it's hard to remember. And it's completely unacceptable that these actions result in the corrupted database. You really should catch ArrayIndexOutOfBoundsException everywhere in order to save database from being corrupted. Terminal client stacktrace: > optimize Possible bug? Feedback is welcome: basex-talk(a)mailman.uni-konstanz.de BaseX 6.3: java.lang.ArrayIndexOutOfBoundsException: -1 org.basex.data.PathSummary.add(PathSummary.java:68) org.basex.core.cmd.Optimize.stats(Optimize.java:68) org.basex.core.cmd.Optimize.run(Optimize.java:34) org.basex.core.Command.run(Command.java:236) org.basex.core.Command.exec(Command.java:218) org.basex.core.Command.execute(Command.java:66) org.basex.server.ServerProcess.run(ServerProcess.java:161) > open products Out of Main Memory. Best regards, Ivan

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Empty Initial Document Inconsistencies
by Dave Glick 05 Jul '12

05 Jul '12

Hello again, I've noticed some inconsistencies with regard to the initial document in an empty database. I understand that it is often treated as an indication that the database is "empty". I.e., if the database has only one node and it's a document at the first pre value, then Data.empty() returns true. The problem arises because the database isn't actually empty - it contains one empty document - and some commands/methods view it as an empty database while others treat it as a database with one empty document. Several examples: - The method Data.doc(name) will return -1 (indicating the document doesn't exist) while Data.docs() will return an array of size 1 with the first value a 0 (indicating there is one document at pre value 0). This is actually my own problem because the API I'm writing relies on these two methods being internally consistent - I can't have one telling me there is one document called "XYZ" but then have the other refuse to give me a pre value for the "XYZ" document I was just told exists. - The GUI shows a single doc node in the tree view but issuing the command "list [database name]" shows the database as having no resources. - I can evaluate the query "insert node 'text' into doc('[initial document name]')" and it executes. I can see the new text node under the initial document in the GUI tree view. Now when I issue the command "list [database name]" I see 1 resource. Having the list command report different numbers of resources before and after a XQuery insertion seems odd. - If I issue the command "ADD TO newdoc <xyz/>", I can see the new doc("newdoc") node with the child <xyz> element in the GUI but the previously empty document is now gone. This also seems odd - I'm not sure how I feel about an ADD command removing data from the database (even if it was just intended to be a placeholder). In the end, I think BaseX should support the notion of a database with one empty document as being valid - there are probably cases where one might want to start their session in that state. I'm not sure what the solution is or should be (or if it's even something that is worth or needs solving). My own preference would be for the internal indication of an empty database to use a different node kind dedicated for that purpose so there is no confusion whether the single node at pre 0 is an empty initial document or an indication of an empty database. At the very least, I think the inconsistencies above should be corrected - if a single empty document node is intended to signify an empty database and is not actually intended to be part of the database, then you should not see it in the GUI, not be allowed to insert content to it, etc. Dave

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deadlock in BaseXServer 6.2.7
by Godmar Back 23 Jun '12

23 Jun '12

Hi, we're observing that our BaseXServer 6.2.7 deadlocks. The stack traces are here: http://top.cs.vt.edu/~gback/bx/deadlock-6.2.7/basex-deadlock.txt Could you take a look to see if these ring any bells? Has this problem been addressed in a more recent version? - Godmar

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index features
by Cerstin Mahlow 14 Feb '12

14 Feb '12

Hi, I have three questions concerning working with the full-text index: The first question is about "distance" information. Given this query: (1) 'contains text "Kopf Sand Stecken" all words using stemming using language "de"' There is no difference to: (2) 'contains text ("Nase" ftand "Sand" ftand "stecken") using stemming using language "de"' both queries deliver 4 nodes. If I would like to find the query terms within a certain distance, adding 'distance at most 10 words' for (1) I get 2 nodes (a subset of the 4 from the first run), but for (2) I still get all 4 nodes. The information concerning distance doesn't seem to be considered. For my application this is no problem, since I have to go for the "ftand"-variant to get proper marking, but in general this looks strange. The second question is about "ftand" and "ftor". If I try these queries: (3) 'contains text ("Nase" ftand "Sand" ftand "stecken") using stemming using language "de" distance at most 10 words' (4) 'contains text ("Kopf" ftand "Sand" ftand "stecken") using stemming using language "de" distance at most 10 words I get 2 hits for (3) and 11 for (4). So I assumed I would get 13 hits (the ones from (3) and the ones from (4) when changing the query to: (5) 'contains text (("Nase" ftor "Kopf") ftand "Sand" ftand "stecken") using stemming using language "de" distance at most 10 words' However, I get 6 hits -- none of them containing "Nase" (there is no difference, if the query starts with '"Nase" ftor "Kopf"' or with '"Kopf" ftor "Nase"'). Did I mess something up? The third question is about the full-text index itself. When applying fuzzy search or using wildcards, the full-text index is not applied -- resulting in a time out on my website, I need 341859.09 ms in the GUI for applying 'ft:mark (//*[text() contains text ("Korb" ftand "geben") using fuzzy][self::*:p or self::*:l])' to my 3 GB collection. The information at the "Full-Text" tab says: - Structure: Trie - Stemming: ON - Case Sensitivity: ON - Diacritics: ON - Language: German - Size: 1 GB - Entries: 1743744 I created the full-text index with the option "Support Wildcards", too, but this information is not shown in the Database properties. When creating the index, "SET WILDCARDS true" is shown. I used stemming, casesensitivity, diacritics, and wildcards -- is this an unrecommended combination? Thank you very much in advance Cerstin -- Dr. phil. Cerstin Mahlow Universität Basel Deutsches Seminar Nadelberg 4 4051 Basel Schweiz Tel: +41 61 267 07 65 Fax: +41 61 267 34 40 Mail: cerstin.mahlow(a)unibas.ch Web: http://www.oldphras.net ---------------------------------------------------------------- This message was sent using IMP, the Internet Messaging Program.

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a few questions about BaseX as an embedded db
by Anders Hessellund 02 Feb '12

02 Feb '12

Hi, I am experimenting with BaseX and have so far built a little toy application that uses an embedded BaseX database. All xml-files in a certain folder, e.g., c:\myXml, is added to the database using the Create and Add commands. This works fine and I can run interesting (and efficient) queries on this. Now we get to my questions: 1. Next time I start my application, I do not want to rebuild the database so I simply connect using the Open command. How do I make sure that the BaseX representation/indexes are synched with the actual XML files in the c:\myXml folder? Does this happen automatically as a side-effect of Open or do I need to take some steps? I am particularly concerned about the case where other programs have manipulated the files when my app was shutdown. 2. Is it possible to do any parts of creating, adding, and opening concurrently? 3. Is it possible to cache results (full or partial) of XQueries? 4. Is it possible to attach schema validation? I do not mind hacking a bit. It seems like there is a SAXHandler available (new Set(Prop.INTPARSE, "false")), could I possibly override that implementation? Cheers, Anders

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Re: [basex-talk] Two tags in different namespaces with same name
by Christian Grün 01 Feb '12

01 Feb '12

Dear Philipp, I didn't manage to reproduce the issue straight off, so... could you create a small sample XML document that will allow me to reproduce the issue? Thanks, Christian ________________________________ On Wed, Feb 1, 2012 at 12:06 AM, Philipp Hitzler <philipp.hitzler(a)bettermarks.de> wrote: > Hello, > > I recently discovered with delight baseX XML Database. I fired all kind of > XQueries and was pleased how fast the output popped up in the text window. > Now I came across something strange. I have two tags in different namespaces > with same name, e.g. > > edl:skill and tdl:skill > > In the GUI command window I wrote > > declare namespace tdl="http://www.bettermarks.com/TDL"; > declare namespace edl="http://www.bettermarks.com/EDL"; > //edl:skill > > and the edl:skill tags/nodes showed up. > > Then I tried > > > declare namespace tdl="http://www.bettermarks.com/TDL"; > declare namespace edl="http://www.bettermarks.com/EDL"; > //tdl:skill > > and the result set was unexpectedly empty. > This was in BaseX 7.0.2 on Windows 7. > > After that I tried a bit and decided to install the latest snapshot. This > time I searched for //tdl:skill first, same command as above, and found the > expected tags. But the search for //edl:skill yielded not any result. It > feels like the first search "blocks" the second, but maybe/probably there > quite different reasons behind this. > > I hope I chose the right directory to send my dear problem in and I gladly > provide more information on my system, database etc. if needed. > > Kind regards, Philipp > > > -- > Using Opera's revolutionary email client: http://www.opera.com/mail/

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select a node result in php and xquery
by Nafiz Al Naharul Islam Grameenphone IT Ltd. 31 Jan '12

31 Jan '12

Dear All, I'm using factbook.xml and in php trying to return a node value in php and xquery. The xquery is fine in basex GUI mode but not working in php Here is the php code ........................... <?php include("BaseXClient.php"); $CMD_OPEN = "open input"; $xq = "XQUERY //mondial/lake[@id='f0_39401']"; try { $session = new Session("localhost", 1984, "admin", "admin"); $session->execute($CMD_OPEN); print $session->execute($xq); $session->close(); } catch (Exception $e) { print $e->getMessage(); } ?> I'm waiting for your early response as it's my course assignment and left very few hours :(. Regards, Nafiz -Al Naharul Islam ________________________________ The information contained in this email and any attachment(s) to this email are intended for the exclusive use of the addressee(s) and may contain proprietary, confidential or privileged information. If you are not the intended recipient and have received this email and/or its attachment(s) in error, you are notified that disclosing, copying, distributing or taking any action in reliance on the contents of this email and/or its attachment(s) is strictly prohibited. Please notify the sender immediately and delete this email and any attachments. WARNING: Computer viruses can be transmitted via email. Although GPIT has taken reasonable precautions to ensure no viruses are present in this email and/or its attachment(s), GPIT does not guarantee that this email and/or its attachments are secure or error-free. The recipient should check this email and any attachment(s) for the presence of viruses. GPIT shall accept no liability whatsoever for any loss or damage arising from the use of this email and/or its attachment(s).

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add to mailing list
by Nafiz Al Naharul Islam Grameenphone IT Ltd. 30 Jan '12

30 Jan '12

Dear Concern, Please add my mail address to your mail group. Regards, Nafiz -Al Naharul Islam System Engineer Charging & Invoicing | Communication Solutions| Technology [cid:image001.png@01CCDF2F.AAB6DEB0] Mobile: +8801711082652 e-mail: nnislam(a)gpit.com<mailto:monwarul.islam@gpit.com> web: www.gpit.com<http://www.gpit.com> ________________________________ The information contained in this email and any attachment(s) to this email are intended for the exclusive use of the addressee(s) and may contain proprietary, confidential or privileged information. If you are not the intended recipient and have received this email and/or its attachment(s) in error, you are notified that disclosing, copying, distributing or taking any action in reliance on the contents of this email and/or its attachment(s) is strictly prohibited. Please notify the sender immediately and delete this email and any attachments. WARNING: Computer viruses can be transmitted via email. Although GPIT has taken reasonable precautions to ensure no viruses are present in this email and/or its attachment(s), GPIT does not guarantee that this email and/or its attachments are secure or error-free. The recipient should check this email and any attachment(s) for the presence of viruses. GPIT shall accept no liability whatsoever for any loss or damage arising from the use of this email and/or its attachment(s).

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session.execute("CREATE DB test inputFolder"); => java.io.IOException: Stream Closed
by Johann LEGAYE 27 Jan '12

27 Jan '12

Hello, I'm new on this mailing list and I have a problem when running on my java app : session.execute("CREATE DB test inputFolder"); because after 20 minutes (my input folder is something like 800 Mo). I got this error message in my console : java.io.IOException: Stream Closed java.io.FileOutputStream.writeBytes(Native Method) java.io.FileOutputStream.write(FileOutputStream.java:305) org.basex.server.Log.write(Log.java:74) org.basex.server.ClientListener.quit(ClientListener.java:240) org.basex.server.ClientListener.run(ClientListener.java:170) What can I do to resolve this ? Thanks a lot ! Johann

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GUI query editor --> revert file
by Piotr Bański 27 Jan '12

27 Jan '12

Hi all, I have an feature request for the GUI editor (veeery handy for testing, thanks!): make it possible to revert files from disk. I have a file open in it that I want to update, because it got modified externally. But I can't -- not even if I open the open-file dialog and try to open it again, as if. No go, the old version sits in the editor still, and I was lucky not to overlook this fact or else I wouldn't know why it doesn't work. Thanks for considering this, and thanks for your work on BaseX, Piotr

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