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5251 discussions

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)) =====

4 5

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>

4 15

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

2 9

Bug (?) in fn:generate-id
by Hans-Juergen Rennau 31 Aug '18

31 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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