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

Large updating query
by Huib Verweij 31 Oct '10

31 Oct '10

Hi BaseX-ers, I'm running into an out-of-memory error when running an updating query over (almost) every document in the database. Every doc has the form <root> <entry><node3/><node2/>...</entry> <entry><node2/><node1/>...</entry> ... </root> I am reordering the elements in every <entry/> element in every document (e.g. <node1/><node2/><node3/>). The query is easy enough to write, it reorders the elements in every <entry/> and replaces the <entry/> in the document with the reordered <entry/>. It works for just one document, but as I said, the db keels over when applying the query to every document. (I am not using any doc() function by the way, just matching on the top level <root/> node.) Do you have a suggestion how I could make this work? I've looked at the documentation on the BaseX website about XQuery Update, but frankly, I do not really understand the bit about documents not being updated, I just select a node from the database, update it, works fine... I must be missing something... (the point probably ;-)). I am using the basex REST api. Huib Verweij.

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Working with indices
by Jan Vlčinský 29 Oct '10

29 Oct '10

Hi I have a bigger collection DDR-All Database Properties Name: DDR-All Size: 743 MB Nodes: 33340760 Height: 8 Database Creation Source Path: D:/var/TICEReports/JSDI data/bezne Time Stamp: 26.10.2010 02:08:30 Input Size: 542 MB Encoding: utf-8 Documents: 79313 Whitespace Chopping: ON Entity Parsing: OFF Indexes Path Summary: ON Text Index: ON Attribute Index: ON Full-Text Index: OFF When I run xquery count(//MSG) it shows result 511990, which is correct. However, it takes a lot of time to produce that result. I thought, that with existing indices it shall bring the result in seconds, and not in minutes (like 10 minutes) Note, that I have created the collection before 6.3 was released, so this might be the case and I would have to import it all again. I was trying to run xquery, using indices xquery basex:index('MSG', 'path') xquery basex:index('//MSG', 'path') but I got a feeling, I do not got it properly, as it responds "Unknown index path" What I would like to know is - names of indices available - what is basex:index function usable for and for what it is not - can I create my own indices? Like calculating date from dateTime fileds in XML. I guess it is not supported. - any further reading? Most of the description is related to full text, but this is not my case. Jan PS: Despite of some performance problems (query lasting 25 minutes) I was able to dig out some very valuable information, which would be inefficient and probably much more error prone in any other way. http://janvlcinsky.s3.amazonaws.com/projects/Monitor/websamples/timeplot/tg… -- *Jan Vlčinský* Slunečnicová 338/3, 734 01 Karviná Ráj, Czech Republic tel: +420-597 602 024; mob: +420-608 979 040 skype: janvlcinsky; GoogleTalk: jan.vlcinsky(a)gmail.com

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Re: [basex-talk] Joins
by Christian Grün 28 Oct '10

28 Oct '10

Hi Patrick, > it is possible to connect two or more xml-databases with one xquery join in BaseX? That's no problem; here's an arbitrary example: for $a in basex:db('db1')//one for $b in basex:db('db2')//two where $a/@id = $b/@id return .... Mails to our mailing list are preferred; as this might be of general interest, I also passed this on to our list. Hope this helps, Christian > I did not find any possibilities to use this feature :( > > Thank you a lot. > > Patrick

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Empty collection reports 1 document
by Jan Vlčinský 27 Oct '10

27 Oct '10

Hi Collection with none and one document inside reports the same count of documents: 1 > create db Test3 Database 'Test3' created in 119.19 ms. > xquery count(collection('Test3')) 1 Query executed in 0.43 ms. > xquery for $doc in collection("Test3") return base-uri($doc) file:/D:/opt/BaseX/Test3 Query executed in 0.74 ms. > xquery / Query executed in 0.33 ms. > add as xml.xml <root/> Path 'xml.xml' added in 3.67 ms. > xquery / <root/> Query executed in 1.1 ms. > xquery count(collection('Test3')) 1 Query executed in 0.54 ms. > With best regards Jan PS: If I should fill it to some bug tracking tool, just let me know where I can find it. Sourceforge? -- *Jan Vlčinský* Slunečnicová 338/3, 734 01 Karviná Ráj, Czech Republic tel: +420-597 602 024; mob: +420-608 979 040 skype: janvlcinsky; GoogleTalk: jan.vlcinsky(a)gmail.com

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How to output plain text (CSV) from XQuery
by Jan Vlčinský 27 Oct '10

27 Oct '10

Hi According to what I found it might be quite implementation specific. In http://www.stylusstudio.com/xquerytalk/201004/003992.html I found some instructions Using Saxon: declare namespace saxon = "http://saxon.sf.net/"; declare option saxon:output "indent=no"; declare option saxon:output "method=html"; Using eXist: declare namespace exist = "http://exist.sourceforge.net/NS/exist"; declare option exist:serialize "method=html indent=no" Is there any simple trick to do that? Thanks Jan -- *Jan Vlčinský* Slunečnicová 338/3, 734 01 Karviná Ráj, Czech Republic tel: +420-597 602 024; mob: +420-608 979 040 skype: janvlcinsky; GoogleTalk: jan.vlcinsky(a)gmail.com

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Removing document from collection erases indexes
by Ivan Lagunov 26 Oct '10

26 Oct '10

Hello, Is it the correct behavior that indexes are automatically removed when I remove a document from a collection (version 6.3)? I mean text and attribute indexes, I haven't tried full-text index. Best regards, Ivan Lagunov

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How to get base-uri under my control
by Jan Vlčinský 26 Oct '10

26 Oct '10

Hi I am adding new documents to collection and would like to have base-uri without prefix of BaseX startup location > add as 3ndtest to \special\path <root/> Path '3ndtest' added in 3.88 ms. > xquery for $doc in collection() return base-uri($doc) file:/D:/opt/BaseX/second.xml file:/D:/opt/BaseX/second.xml file:/D:/opt/BaseX/s econd.xml file:/D:/opt/BaseX/second.xml file:/D:/opt/BaseX/third.xml file:/D:/op t/BaseX/third.xml file:/D:/opt/BaseX/third.xml file:/D:/opt/BaseX/test file:/D:/ opt/BaseX/2ndtest file:/D:/opt/BaseX/path/3ndtest file:/D:/opt/BaseX/special/pat h/3ndtest file:/D:/opt/BaseX/special/path/3ndtest file:/D:/opt/BaseX/special/pat h/3ndtest Query executed in 2.68 ms. > I tried many ways how to specify target - without and with slash and backslash - no change. Is there any way to manage that? Jan Vlčinský PS: Be sure this is not a problem if it is not possible. it would be only a bit nicer.

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nosql-database.org
by Charles F. Munat 26 Oct '10

26 Oct '10

Because BaseX was missing from the list at http://nosql-database.org/ , I took the liberty of adding it. There was a 330 char limit on the description, so I swiped some stuff from the home page and tightened it up to fit. If anyone at BaseX would prefer a different description, let me know or send it to the folks at nosql-database.org. And congrats on the latest release. Good features and reliability, Java, and the ability to use BaseX with Maven make it my XML DB of choice. Chas.

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Re: [basex-talk] Index issue for a large collection
by Ivan Lagunov 25 Oct '10

25 Oct '10

Hi Oliver, I tried both GUI mode and terminal client. I get the same error there. And also Map Visualization worked fine for the same collection before I created indexes. Don't you have the same problem in terminal mode? How big is your collection then (number of files and size in MB)? Best regards, Ivan 20.10.2010 18:21, Oliver Egli wrote: > Hi Ivan, > > I used to have the same problem. If you are working with the GUI mode, try > to close the Map Visualization. (Open another smaller DB, close the > Visualization, and try to open your Database again). > That worked fine for me. > > Regards, Oli > > -----Ursprüngliche Nachricht----- > Von: basex-talk-bounces(a)mailman.uni-konstanz.de > [mailto:basex-talk-bounces@mailman.uni-konstanz.de] Im Auftrag von Ivan > Lagunov > Gesendet: Mittwoch, 20. Oktober 2010 16:00 > An: Christian Grün > Cc: BaseX Talk > Betreff: [basex-talk] Index issue for a large collection > > Hi, > > I have a database collection with over 17000 documents (about 190MB in > total). Everything worked fine until I created text and attribute > indexes to improve performance. Now I cannot open database and perform > any operation with it because I get 'Error: Out of Main Memory'. Setting > "intparse on" doesn't help. I've increased Xmx value up to 2560m > (maximum value for my system), it doesn't help too. Is there any way to > fix it? Could you provide an approximate size of memory that is required > for text and attribute indexes depending on the size of the database? Is > there any possibility for me to use indexes on current system? Thanks in > advance! > > Best regards, > Ivan > > _______________________________________________ > BaseX-Talk mailing list > BaseX-Talk(a)mailman.uni-konstanz.de > https://mailman.uni-konstanz.de/mailman/listinfo/basex-talk > >

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Congratulations
by NewIntellectual 25 Oct '10

25 Oct '10

Congratulations to the hard working BaseX team for releasing BaseX 6.3. I haven't found a more powerful or useful XML database system. I know of very few open source software projects that are as attentive to problems, and as rapidly making improvements, as BaseX.

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