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

REPLACE command issue in Basex version 8.6.6/9.0.2
by Stephan van Hugten 01 Oct '18

01 Oct '18

In our software we're using a Basex database and integrate with it via the Java library. We're currently using 8.0.3, but attempted to upgrade to the latest version (9.0.2) when we encountered a breaking issue. The REPLACE command class now interprets all XML with an attribute as a path. I can reproduce this in the basex command line client, but not the GUI. Reproducer case: BaseX 9.0.2 [Client] Try 'help' to get more information. > create db test Database 'test' created in 25.24 ms. > open db test Database 'db' was not found. > open test Database 'test' was opened in 1.57 ms. > REPLACE com.example.model.user.Account-2397 "<text version="draft"><title>Chapter</title></text>" Resource "C:/Java/basex902/bin/"<text version=draft><title>Chapter</title></text>"" not found. > REPLACE com.example.model.user.Account-2397 <text version="draft"><title>Chapter</title></text> Resource "C:/Java/basex902/bin/"<text version=draft><title>Chapter</title></text>"" not found. > REPLACE com.example.model.user.Account-2397 <text version='draft'><title>Chapter</title></text> Resource "C:/Java/basex902/bin/"<text version='draft'><title>Chapter</title></text>"" not found. > REPLACE "com.example.model.user.Account-2397" <text version='draft'><title>Chapter</title></text> Resource "C:/Java/basex902/bin/"<text version='draft'><title>Chapter</title></text>"" not found. > REPLACE "com.example.model.user.Account-2397" "<text version='draft'><title>Chapter</title></text>" Resource "C:/Java/basex902/bin/"<text version='draft'><title>Chapter</title></text>"" not found. > REPLACE top.xml "<text version='draft'><title>Chapter</title></text>" Resource "C:/Java/basex902/bin/"<text version='draft'><title>Chapter</title></text>"" not found. > REPLACE top.xml <xml/> 0 resource(s) replaced in 29.71 ms. > REPLACE top.xml <xml version='draft'/> Resource "C:/Java/basex902/bin/"<xml version='draft'/>"" not found. > Storing the XML in a file and replacing that works: > REPLACE com.example.model.user.Account-95 test.xml 1 resource(s) replaced in 5.03 ms. > xquery //account <account uuid="83ff82e4-01b1-4624-969e-2ba7e7deeb29" id="10095"><x/></account> Can you assist in solving this mystery? '************************************************************************************************** This E-mail and any files transmitted with it are private and confidential and are solely for the use of the addressee. It may contain material which is legally privileged. If you are not the addressee, be advised that you have received this E-mail in error and that any use of it is strictly prohibited. If you have received this E-mail in error, please notify APS on +44 (0)161 495 4500, or E-mail administrator(a)theapsgroup.com. Any opinions expressed in the E-mail are those of the individual writer of it and not necessarily the Company unless specifically stated otherwise. There is no intention to create any legally binding contract or other commitment through use of this E-mail We cannot accept any liability for any loss or damage sustained as a result of software viruses. It is your responsibility to carry out such virus checking as is necessary before downloading this E-mail and any attachments onto your computer system. Allied Publicity Services (Manchester) Ltd Registered Office: Allied Publicity Services (Manchester) Ltd, Chetham House, Bird Hall Lane, Cheadle Heath, Cheshire, SK3 0ZP Company Registration No: 681528 England APS Group Secure Solutions Limited. Registered Office: Chetham House, Bird Hall Lane, Stockport, Cheshire, SK3 0ZP Company Registration No: 07007434 England APS Group (Scotland) Ltd. Registered Office: APS Group (Scotland) Ltd, 21. Tennant Street, Edinburgh, EH6 5NA Company Registration No: SC369510 Scotland ______________________________________________________________________ This email has been scanned by the Symantec Email Security.cloud service. For more information please visit https://www.symantec.com ______________________________________________________________________

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JAVA xquery: accessing documents
by Jan Stapel 01 Oct '18

01 Oct '18

Hello, Normally (few basex-versions ago) I did: session.execute("open main"); session.execute("xquery doc("users.xml")//users"); But now, this results in basex interpreting the doc()-path as relative to it's home-directory thus cannot find the resource.. "xquery doc("main/users.xml")//users" gives the correct results. Do we no longer open a database but writing the full path of the document instead? Whats the performance of this if accessing multiple documents of the same database during runtime? -regards, jan

2 1

XML catalog with fetch:xml
by Andy Bunce 25 Sep '18

25 Sep '18

Hi, Using a recent 9.1 Beta on windows. I create an XML catalog at c:\tmp\mycatalog.xml <catalog prefer="system" xmlns="urn:oasis:names:tc: entity:xmlns:xml:catalog"> <uri name="http://nowhere.com/doc" uri="file:///c:/tmp/doc.xml" /> </catalog> Then in the GUI fetch:xml("http://nowhere.com/doc", map{"catfile": "C:\tmp\mycatalog.xml"} ) It goes to nowhere, I was hoping to get back c:/tmp/doc.xml Should this work? /Andy

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Importing XML (DITA) validated with Relax NG schemas?
by Robert Crews 25 Sep '18

25 Sep '18

I'm trying to set up BaseX to manage a repository of DITA content. The DITA content has been specialized to validate against Relax NG schemas instead of DTDs. While importing content that validate against DTDs is straight forward, I have not yet figured out the best way to import Relax NG based content. So, I have a few questions: * I see there is the Validation module [1] and that's good because I think XQuery is my best option for managing the imports. However, I need to pass a specific schema to the functions. DITA content utilizes multiple schemas. Is there some way I can pass a directory to these functions instead of just a single file reference? * I currently have the CATFILE option set [2]. Does this help or hinder importing when choosing to validate against Relax NG? Is there some way I can set the global options to make validating against Relax NG easier? * I've seen multiple examples of people actually storing the schema(s) in the database. Is that necessary or help for using the validation module? Thanks for your help! [1] http://docs.basex.org/wiki/Validation_Module#RelaxNG_Validation [2] http://docs.basex.org/wiki/Catalog_Resolver http://docs.basex.org/wiki/Options#CATFILE For reference, here is how Oxygen handles catalog resolution<https://www.oxygenxml.com/doc/versions/20.1/ug-editor/topics/using-XML-Cata…>. See the bottom of Table 1. Catalog Mappings for a summary of how Relax NG is resolved.

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BaseX GUI repo install shortcut
by Marco Lettere 25 Sep '18

25 Sep '18

Hi Christian et al, I'm not aware of any shortcut (keyboard, flag or any) for speeding up the reinstallation of a REPO module once the XQ file is being updated when working in the GUI. At the moment I always reinstall from the preference menu but when developing in continuous it's a bit tedious and often I forget it and have to switch back from my test environment to reinstall. Is there any way or could you think of any good shortcut to (at least partially) automate the reinstall procedure after updating the .xqm module in a GUI tab? Thanks, Marco.

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Tomcat and UserPrincipal
by Marco Lettere 25 Sep '18

25 Sep '18

Hi all, when deploying a BaseX RestXQ module as a Tomcat webapp in a container that uses embedded realm based authentication is there any way to retrieve the login name after being redirected to the protected page? I remember back in J2EE times there was a dedicated method getUserPrincipal. Is there any equivalent using "request:"? Thanks as usual for any kind support! Marco.

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Should serialize function take "newline" : "\r\n" option in the map parameter into account?
by Martin Honnen 25 Sep '18

25 Sep '18

When I run contains(serialize("Line 1.
Line 2.
Line 3.", map { "method" : "text", "newline" : "\r\n" }), '') in BaseX 9.0.2 (from the command line basex.bat or in the GUI) I get the result "false" while I expected "true". Have I not provided the newline option correctly?

2 1

Minor PR/fix suggestion
by Bridger Dyson-Smith 24 Sep '18

24 Sep '18

Hi Christian, et al, I'm guessing that you're all busy with working towards a 9.1 release (yay!), but if you have time would you consider an incredibly minor PR? I recently noticed that the BaseX GUI supports completion and it's great. I found a small typo in the completions: `sliding=for tumbling window` should be `sliding=for sliding window` It's super-duper simple, but I have a branch with the typo fixed[1]. In any event, thanks! Looking forward to the next release. Best, Bridger [1] https://github.com/CanOfBees/basex/tree/fix-completions-typo

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Optimize broke my database(s)
by Florian Wagner 24 Sep '18

24 Sep '18

Hey everone, we're close to going live with a project built upon BaseX with largish Databases (the biggest one being about 6 GB unoptimized). We have a regular nightly full-optimize job. One run this weekend seems to have broken two of our databases. There's single error message per broken database in our logs: java.io.FileNotFoundException: /var/db/basex/[...]_1151592207/inf.basex (No such file or directory) at java.io.FileOutputStream.open0(Native Method) at java.io.FileOutputStream.open(FileOutputStream.java:270) at java.io.FileOutputStream.<init>(FileOutputStream.java:213) at java.io.FileOutputStream.<init>(FileOutputStream.java:162) at org.basex.io.IOFile.outputStream(IOFile.java:158) at org.basex.io.out.DataOutput.<init>(DataOutput.java:47) at org.basex.io.out.DataOutput.<init>(DataOutput.java:36) at org.basex.data.DiskData.write(DiskData.java:137) at org.basex.data.DiskData.close(DiskData.java:160) at org.basex.core.cmd.OptimizeAll.optimizeAll(OptimizeAll.java:145) at org.basex.query.up.primitives.db.DBOptimize.apply(DBOptimize.java:124) at org.basex.query.up.DataUpdates.apply(DataUpdates.java:175) at org.basex.query.up.ContextModifier.apply(ContextModifier.java:120) at org.basex.query.up.Updates.apply(Updates.java:157) at org.basex.query.QueryContext.iter(QueryContext.java:346) at org.basex.query.QueryProcessor.iter(QueryProcessor.java:90) at org.basex.core.jobs.QueryJob.run(QueryJob.java:165) at java.lang.Thread.run(Thread.java:748) The DBAs "Databases" page still lists the broken dbs including the size and a last-modified date of the Job time. But clicking them gets you a detail page with no details, documents, no Add... / Delete / Copy.. buttons and the backup buttons being disable. Ideas how to go from here are greatly appreciated? Any chance getting our database contents back? Grüße Florian Wagner --- Universitaetsbibliothek Tuebingen Wilhelmstr. 32, 72074 Tuebingen IT-Abteilung, Raum B102 +49(0)7071/29-77860 http://www.ub.uni-tuebingen.de

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Wiki Question
by Bridger Dyson-Smith 24 Sep '18

24 Sep '18

Hi all - A quick question about a function name in the wiki: is the convert function: `convert:binary-to-integer()` or `convert:binary-to-integers()`[1]? Thank you and have a nice weekend! Bridger [1] http://docs.basex.org/wiki/Conversion_Module#convert:binary-to-integers

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.basex setup
by kalibuk＠centrum.cz 24 Sep '18

24 Sep '18

Hi all, I'm wondering with my colleague Radim how to setup settings in .basex file. We have not found any detailed documentation what the concrete field set. We had problems with interrupting file upload to database so we played around and so changing the PARALLEL from 8 to 60(!) helped. Also increasid CACHETIMEOUT and TIMEOUT for different reasons. Anybody have detailed documentation of what we set up, what all it affects, what are the ranges of values, and such for these settings? Regards, Jan

2 1

basexhttp errors
by radim-havlicek＠post.cz 20 Sep '18

20 Sep '18

Hello. When I start basexhttp.bat, following errors display: Starting Process basexhttp SLF4J: Class path contains multiple SLF4J bindings. SLF4J: Found binding in [jar:file:/C:/Program%20Files%20(x86)/BaseX/lib/slf4 j-simple-1.7.13.jar!/org/slf4j/impl/StaticLoggerBinder.class] SLF4J: Found binding in [jar:file:/C:/Program%20Files%20(x86)/BaseX/lib/slf4 j-simple-1.7.25.jar!/org/slf4j/impl/StaticLoggerBinder.class] SLF4J: See http://www.slf4j.org/codes.html#multiple_bindings for an explanation. SLF4J: Actual binding is of type [org.slf4j.impl.SimpleLoggerFactory] [main] WARN org.eclipse.jetty.xml.XmlConfiguration - Config error at <Call name="addConnector"><Arg> <New id="httpConnector" class="org.eclipse.jetty.server. ServerConnector"><Arg name="server"><Ref refid="Server"/></Arg><Set name= "host">0.0.0.0</Set><Set name="port">8984</Set><Set name="idleTimeout">60000 </Set><Set name="reuseAddress">true</Set></New> </Arg></Call> java.lang.IllegalStateException: No object for id=null How can I correct it? Thank you in advance for your help. Best regards, Radim Havlicek

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web:response-header & Set-Cookie
by Bogdan Bogucki 18 Sep '18

18 Sep '18

Hello, When I try invoke following code: return ( web:response-header( map { 'media-type': web:content-type($path) }, map { 'Cache-Control': 'max-age=3600,public' }, map { 'Set-Cookie': 'JSESSIONID=' || session:id() || ';max-age=1800' } ), file:read-binary($path) } I receive error: [XPTY0004] Unknown option 'Set-Cookie'. I am able to set cookie using <rest:response>. Following code is working: return ( <rest:response> <http:response status="200" message="OK"> <http:header name="media-type" value="{web:content-type($path)}"/> <http:header name="Content-Type" value="text/html"/> <http:header name="Cache-Control" value="max-age=3600,public"/> <http:header name="Set-Cookie" value="{'JSESSIONID=' || session:id() || ';max-age=1800'}"/> </http:response> </rest:response>, file:read-binary($path) ) I think function web:response-header should allow set cookie. Regards Bogdan Bogucki

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First non-null value?
by Graydon Saunders 14 Sep '18

14 Sep '18

let $possible1 as xs:string* := (: go looking for a value via one route :) let $possible2 .... (: all the other routes in preference order :) .... let $foundIt as xs:string := ($possible1,$possible2,$possible3,$possible4,$possible5,'FAILED')[1] This works nicely in terms of "I got the value by the least-bad route". What I'm blanking on is "how do I tell which was the first possibility to match?" without resorting to sprawl of if-then-else statements. I have the idea that there must be a compact way but I have no idea what it is if there is. Any suggestions? Thanks! Graydon

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dB:update()
by ＠pyschny.de 12 Sep '18

12 Sep '18

I want to solve the following problem: For $doc in $list-of-docs detect differences in doc against the basex-db and add the changed records to the basex-db. After differences of each doc are added to the basex-dB create a new index for basex-dB which is required for the next $doc How can I solve the problem that the added records are not visible for the index creation? Michael

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comparing basex and csv datasets
by ＠pyschny.de 10 Sep '18

10 Sep '18

Dear basex and xquery experts, I have to solve the following problem: On a daily basis I get data packages in csv format (approx.. 20.000 records) I imported the 1st package to basex-DB and want to import further changed or new records from the daily deliveries. I tried several solutions but cannot get a solution which is performant enough to be executed every day. While importing complete packages takes a few seconds – comparing against records in the database requires hours. So I decided to use the index variant which is described by Christian Grün. My core code looks as follows: let $db = db:open(‘mydb’) let $ndx = db:open(‘mydb-index’) let $xml := csv:parse($csv, map { "header": true(), "separator": ';' }) let $xml := ( for $x in subsequence($xml//record,2) count $c return if( local:recordUpdated( $x, ‘mydb’, $ndx)) then ( element {'record'} { attribute {'recno'} {$c}, $x/child::*} ) else () ) (: Aufnahme der Differenzen in die DB :) db:replace( $dbname, $tpalow||"/"||$seqno, $xml) declare function local:recordUpdated( $rec, $dbname, $ndx as item()*) as xs:boolean { let $id := $ndx//vp[@ptn=$rec/_14_TPA-Key_VP/text() and @tarif=$rec/_28_TPA-Key_Tarif/text()]/id return if( $id) then ( let $oldrec := db:open-id($dbname, $id)/.. return not(deep-equal($oldrec/child::*, $rec/child::*)) ) else true() }; Both databases ‘mydb’ and ‘mydb-index’ are created with attribute and text indexes. After each run the index is newly created to point to the newest records for the given key values. Can anybody point out why this process takes more than a second per each single record to compare? Thanks for your time

1 0

Example xquery needed to write output to an local xml file
by Marco Roling 06 Sep '18

06 Sep '18

Dear all, I am new on the block here, and trying to find my way around BaseX, which seems to meet my needs for my research on digital museum collection data analysis. I have a very large collection of xml files (> 600000 files) that I am querying, and I want to write the returned result immediately in a file. The following xquery (see below) is not working, which probably comes as no surprise to you all. But to get me started, I would like to have a simple example that works. Any example would do. Hope anyone can help me out with this. Thanks very much, best, Marco. ===== declare variable $data := collection(PRODRMCollectionItems); declare variable $output := 'C:\DATAQUERY\BaseX\Q001\outputPROD'; (:This is where all the work is happening:) declare function local:process-data ($nodes as item()*) as element (root) { <RMCollectionItemsDATA created="{current-dateTime()}"> { for $a in $nodes//artObjectGetResponse/artObject[objectNumber eq 'NG-NM-1395-A'] return <item>{$a}</item> } </RMCollectionItemsDATA> }; (:here we store stuff:) let $filename := concat($output, "marco.xml") return file:write($filename, local:process-data($data)) =====

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diacritics sensitive not working
by Ron Katriel 03 Sep '18

03 Sep '18

Hi, The following from your website (docs.basex.org/wiki/Full-Text) appears to be syntactically incorrect "'Äpfel' will not be found..." contains text "Apfel" diacritics sensitive In the BaseX GUI the keyword diacritics is underlined in red and the following error is reported Unexpected end of query: 'diacritic sens...'. This happens in version 8.6.4 and also the latest (9.0.2). Thanks, Ron *Ron Katriel, Ph.D. *| Principal Data Scientist | Medidata Solutions <http://www.mdsol.com/> 350 Hudson Street, 7th Floor, New York, NY 10014 rkatriel(a)mdsol.com <tbrophy(a)mdsol.com> | direct: +1 201 337 3622 <//201%20337%203622> | mobile: +1 201 675 5598 <//mobile:%20+1%20201%20675%205598> | main: +1 212 918 1800 <//+1%20212%20918%201800>

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BaseX insert/delete node performance
by BIRKNER Michael 01 Sep '18

01 Sep '18

Hello, I asked this question in StackOverflow concerning some performance problems I experienced when inserting nodes into a BaseX database: https://stackoverflow.com/questions/51595210/basex-inserting-nodes-performa… I already made some progress, especially when it comes to querying all data I need for the updates. I work a lot with the indexes now. But I still have problems with inserting - and also deleting - nodes. It doesn't matter if I insert/delete nodes via a Java program or in the editor of the BaseX GUI: Both is quite slow. Inserting just one node in the GUI with an XQuery like this one takes up to 3 seconds: insert node <related_record><title>Test title</title><author>Joe Lastname</author></related_record> into db:open-id('Database_Name', 7947561) Deleting a node with the following command takes up to 7 seconds: delete node db:open-id('Database_Name', 88085737) The problem is that in my case, I have to do about 150000 inserts and deletes, so it would take too much time. Maybe my database is just too big to be performant? Or some settings are wrong? I'm very new to BaseX (and XML databases in general) so maybe there are just some errors I don't see. I also give you some information on my database that I copied from the info screen of the BaseX GUI: Database Properties NAME: Database_Name SIZE: 2568 MB NODES: 135607105 DOCUMENTS: 1 BINARIES: 0 TIMESTAMP: 2018-08-07T07:05:56.000Z UPTODATE: true Resource Properties INPUTPATH: /path/to/file.xml INPUTSIZE: 1774 MB INPUTDATE: 2018-07-24T14:32:58.000Z Indexes TEXTINDEX: true ATTRINDEX: true TOKENINDEX: false FTINDEX: false TEXTINCLUDE: ATTRINCLUDE: TOKENINCLUDE: FTINCLUDE: LANGUAGE: English STEMMING: false CASESENS: false DIACRITICS: false STOPWORDS: UPDINDEX: true AUTOOPTIMIZE: false MAXCATS: 100 MAXLEN: 96 SPLITSIZE: 0 Best regards, Michael Beachten Sie, dass Sie uns ab sofort unter einer geänderten Rufnummer erreichen. Bitte speichern Sie gleich Ihren Kontakt zur AK Wien ein unter 501 65 1, gefolgt von der gewohnten Durchwahl. Dieses Mail ist ausschließlich für die Verwendung durch die/den darin genannten AdressatInnen bestimmt und kann vertrauliche bzw rechtlich geschützte Informationen enthalten, deren Verwendung ohne Genehmigung durch den/ die AbsenderIn rechtswidrig sein kann. Falls Sie dieses Mail irrtümlich erhalten haben, informieren Sie uns bitte und löschen Sie die Nachricht. UID: ATU 16209706 I https://wien.arbeiterkammer.at/Datenschutz_(DSGVO).html

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Bug (?) in fn:generate-id
by Hans-Juergen Rennau 30 Aug '18

30 Aug '18

Dear BaseX team, I face an issue with fn:generate-id. Given: a document $doc parsed from the file system.Nodes obtained by xquery_eval(EXPR, map{'':$doc}) and nodes obtained by $doc/EXPR have the same identity (per $node1 is $node2), but the values generated by fn:generate-id differ. Interestingly, if the document is constructed within the query, rather than read from a file, the values generated by fn:generate-id do not differ. For a test see below. At first sight, the issue may appear too obscure to justify efforts to remove it. HOWEVER, there is an important use case involved: (a) expressions are read from a configuration and evaluated via xquery:eval; a map is constructed which associates for each node in the expression value its node id with other information (e.g. which of the configured expressions yielded this node) ;(b) then, when later nodes are visited via XPath, that other information should be retrieved (lookup in the map, using generate-id($node) as key) - AND THIS FAILS, as the XPath-provided nodes have ids which are different from the xquery:eval-provided nodes. Could you please have a look? With kind regards,Hans-Jürgen Test query:======== let $doc1 := <root><foo/><bar/></root> let $doc2 := doc('foobar.xml')/* let $evalNodes1 := xquery:eval('*', map{'': $doc1}) let $evalNodes2 := xquery:eval('*', map{'': $doc2}) let $xpathNodes1 := $doc1/* let $xpathNodes2 := $doc2/* let $evalIds1 := $evalNodes1/concat(local-name(.), ' id=', generate-id(.)) let $xpathIds1 := $xpathNodes1/concat(local-name(.), ' id=', generate-id(.)) let $evalIds2 := $evalNodes2/concat(local-name(.), ' id=', generate-id(.)) let $xpathIds2 := $xpathNodes2/concat(local-name(.), ' id=', generate-id(.)) return ( 'local doc - evalNodes1 = xpathNodes1 ?', for $i in 1 to 2 return $evalNodes1[$i] is $xpathNodes1[$i], '', 'local doc - evalNodes, ids:', $evalIds1, 'local doc - xpathNodes, ids:', $xpathIds1, '', 'file doc - evalNodes1 = xpathNodes1 ?', for $i in 1 to 2 return $evalNodes2[$i] is $xpathNodes2[$i], '', 'file doc - evalNodes, ids:', $evalIds2, 'file doc - xpathNodes, ids:', $xpathIds2) Document 'foobar.xml':================= <root><foo/><bar/></root> OUTPUT:======= local doc - evalNodes1 = xpathNodes1 ? true # OK! true # OK! local doc - evalNodes, ids: foo id=id10 bar id=id12 local doc - xpathNodes, ids: foo id=id10 # OK! bar id=id12 # OK! file doc - evalNodes1 = xpathNodes1 ? true # OK! true # OK! file doc - evalNodes, ids: foo id=id17 bar id=id18 file doc - xpathNodes, ids: foo id=id31 # SHOULD BE id17bar id=id32 # SHOULD BE id18

1 0

DB connection between classes
by Karina C. Malavazi 30 Aug '18

30 Aug '18

Hello, I'm new on Java programming and also on nonSQL database... hope you can give me some support. I have a group of testcases where every time that a test is executed the database has to be connected again, which lets my tests very slow. Example: public class AllTests { . public static Test suite() throws IOException { TestSuite suite = new TestSuite(); suite.addTestSuite(NumberTest.class); suite.addTestSuite(LetterTest.class); suite.addTestSuite(ImageTest.class); ... } } In the example above, NumberTest.class, LetterTest.class and ImageTest.class are tests made for some interfaces that use the same document from the database. However, each one of them finish (NumberTest and LetterTest), I have to connect to the database again. I'm not "closing" it in any place, only opening. So, why is this being closed every time that a new test is executed? Is there any way to keep the db connection opened during all the tests and close it only in the end? Any idea or tip will be helpful. Thanks, Karina.

2 1

rest parallel
by Ветошкин Владимир 29 Aug '18

29 Aug '18

2 9

ThreadLocal error in Tomcat
by Simon Chatelain 29 Aug '18

29 Aug '18

Hello all, I am currently using BaseX in embedded mode as a XQuery processor in a tomcat webapplication. I am receiving some XML, create a BaseX in memory database, execute some XQuery, then close the context. But when I stop tomcat or reload the web application, I have a lot of errors saying: SEVERE [localhost-startStop-2] org.apache.catalina.loader.WebappClassLoaderBase.checkThreadLocalMapForLeaks The web application [webap] created a ThreadLocal with key of type [java.lang.ThreadLocal.SuppliedThreadLocal] (value [java.lang.ThreadLocal$SuppliedThreadLocal@60506a99]) and a value of type [org.basex.query.expr.path.PathCache] (value [org.basex.query.expr.path.PathCache@665cfafa]) but failed to remove it when the web application was stopped. Threads are going to be renewed over time to try and avoid a probable memory leak. Is there a way to avoid that error, by forcibly clearing these cache or something ? Thanks Simon

2 2

Performance (index?) on large intermediate structures
by Sebastian Albert 29 Aug '18

29 Aug '18

Dear BaseX community I am currently working with BaseX to write a rather long XQuery statement with quite large intermediate structures (XML documents / fragments) bound to variables (in FLWOR expressions), which I query by XPath using attributes etc. further down. Having nested loops, this is becoming very slow. Are those intermediate structures automatically indexed? Or how can I achieve indexing on them? Or do I need to write them into a database for this indexing? (Can I specify a datbase as "in-memory"?) Then I guess I need a "BaseX script" rather than a single XQuery? Of course, I am looking for the most elegant/idiomatic way. Or is it best to build index-like intermediate structures myself, probably using maps rather than XML documents? Furthermore, are there profiling tools inside BaseX, or would I need to fire up a Java IDE to see where most time is being spent? Thanks in advance for any suggestions! Sebastian

2 1

[XQUERY] Filter and paging with window clause
by Marco Lettere 28 Aug '18

28 Aug '18

Hi all, here's a question related to XQuery, sorry for being slightly off-topic. I'm struggling to find a way to combine the windowing clause and FLOWR in order to get a paged result of a subset of items which respect a given filter. Of course I'm able to get this by first applying the filter to the whole input and then a second FLOWR for the windowing clause. But I was wondering whether it's possible to streamline this into one single FLOWR. Two bonus questions: 1. Will this actually be more efficient than the naive (two FLOWR) solution or is the almighty optimizer able to blend the two subsequent FLOWR on its own? 2. What if the input is unordered and I also would like to introduce sorting? The closer I get is [1] which is not what I'd need because I get 2,4,6,8,10 as result for page 1 but I'd really want 10 results per page thus 2,4,6,8,10,12,14,16,18,20. Thanks for any help on this in the meanwhile I'll stick to my naive solution. Marco. [1] let $page := 1 let $count := 10 return for tumbling window $w in (1 to 100) start $first at $s when ($s = 1 + ($page - 1) * $count) end $last at $e when ($e - $s = $count - 1) return $w ! (if (. mod 2 = 0 ) then . else ())

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