October 2018 - BaseX-Talk - mailman.uni-konstanz.de

Database Updates
by Dave Kopecek 25 Oct '18

25 Oct '18

Hi All, Given a database created from catalog.xml below. What's the best way to update & add records received daily as in file daily-update.xml ? Coming from relational DBs & new to this. I ultimately need to script/automate this. Hoping there's some magic command I'm missing & looking for best way to approach the problem. Thanks, -Dave catalog.xml <?xml version="1.0" encoding="UTF-8"?> <CATALOG> <ENTRIES> <ENTRY> <SKU>1</SKU> <TITLE>Empire Burlesque</TITLE> <ARTIST>Dylan</ARTIST> <PRICE>10.90</PRICE> </ENTRY> <ENTRY> <SKU>2</SKU> <TITLE>Hide your heart</TITLE> <ARTIST>Bonnie Tyler</ARTIST> <PRICE>9.90</PRICE> </ENTRY> </ENTRIES> </CATALOG> daily-update.xml <?xml version="1.0" encoding="UTF-8"?> <CATALOG> <ENTRIES> <ENTRY> <SKU>1</SKU> <PRICE>19.90</PRICE> <NEWTHING>I wasn't here before the update</NEWTHING> </ENTRY> <ENTRY> <SKU>1971</SKU> <TITLE>Tupelo Honey</TITLE> <ARTIST>Van Morrison</ARTIST> <PRICE>8.20</PRICE> </ENTRY> </ENTRIES> </CATALOG>

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Websocket chat and session
by Maximilian Gärber 24 Oct '18

24 Oct '18

Hi, we've chat working with the 9.1 snapshot. Also private message works but only if the BaseXHTTP class is used (embedded jetty). If we start the webapp with mvn jetty:run the session info seems to get lost (also in the DBA). Br, Max

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Sir, when basex 9.1, please ;-)
by Maximilian Gärber 24 Oct '18

24 Oct '18

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determine index use in xquery:eval
by Johannes Echterhoff 24 Oct '18

24 Oct '18

Hello, Is there a way to determine if the query that is executed by xquery:eval(...) makes use of index information? Can we somehow obtain the optimized plan for that query? Best regards, Johannes

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Re: [basex-talk] Importing XML (DITA) validated with Relax NG schemas?
by Christian Grün 24 Oct '18

24 Oct '18

Hi Jason (cc to the list), > I set the CP variable like so: > CP=$MAIN/BaseX.jar:$MAIN/lib/custom/dita-ng.jar:$MAIN/lib/*:$MAIN/lib/custom/*:$CLASSPATH > > This appears to be slightly different than the example you linked Christian. I’m using BaseX 9.0.2. Does this make a difference? The start scripts in the official distributions are created from the GitHub examples I linked, so they are slightly different. > I added an echo $CLASSPATH line under the CP variable. When I run the script, the echo statement is blank. In the script, no value will be bound to the $CLASSPATH variable. Instead, you can assign values to this variable by yourself, which will then be appended to the $CP variable. If you didn’t do so, and if your Linux environment does not have any other values assigned to this variable (which is the default), the output will necessarily be empty. > Is there a way to see how the classpath is set when running this script? To answer the "how": It will be set via the line that you will find some lines below in the script, and the -cp Java argument: exec java -cp "$CP" $BASEX_JVM org.basex.BaseX "$@" If you want to know which value is bound to $CP, try "echo $CP". In Java, the full user class path at runtime will be bound to the "java.class.path" system property. It can e.g. be retrieved via proc:property('java.class.path') [1]. Christian [1] http://docs.basex.org/wiki/Process_Module#proc:property

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REQUEST REPLACE error
by radim-havlicek＠post.cz 23 Oct '18

23 Oct '18

Hello, we have currently 9 databases in our BaseX database. The biggest ones have about 9 GB, all together they have nearly 26 GB. Everything had worked fine until Friday. Since Friday, every time we sent REQUEST REPLACE command to any of those databases, it generated following error: 00:00:17.672 0.0.0.1:64492 admin REQUEST REPLACE Report\8f6a4b73-5be2-4246-b 0ad-3baaec0fbd54 [...] 4.16 ms 00:00:18.282 0.0.0.1:64492 admin ERROR Improper use? Potential bug? Your feedback is welcome: Contact: basex-talk(a)mailman.uni-konstanz.de Version: BaseX 8.6.3 Java: Oracle Corporation, 1.8.0_171 OS: Windows Server 2012 R2, amd64 Stack Trace: java.lang.ArrayIndexOutOfBoundsException at org.basex.io. random.TableDiskAccess.insert(TableDiskAccess.java:347) at org.basex.data. Data.insert(Data.java:912) at org.basex.data.Data.insert(Data.java:739) at org.basex.query.up.atomic.Insert.apply(Insert.java:44) at org.basex.query. up.atomic.AtomicUpdateCache.applyUpdates(AtomicUpdateCache.java:297) at org. basex.query.up.atomic.AtomicUpdateCache.execute(AtomicUpdateCache.java:281) at org.basex.core.cmd.Replace.replace(Replace.java:104) at org.basex.core. cmd.Replace.access$0(Replace.java:69) at org.basex.core.cmd.Replace$1.run (Replace.java:57) at org.basex.core.cmd.ACreate.update(ACreate.java:90) at org.basex.core.cmd.Replace.run(Replace.java:54) at org.basex.core.Command. run(Command.java:257) at org.basex.core.Command.execute(Command.ja... 612.41 ms (It is from the log file.) We currently use BaseX version 8.6.3 Any idea why the error is generated and what could be the source of the problem? (Too big database? Too big databases all together? Some database lock?) Thank you in advance for your answer. Best Regards, Radim Havlicek

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Fwd: [dita-users] [ANN] XML Prague 2019 - Call for Proposals
by Maximilian Gärber 23 Oct '18

23 Oct '18

Just cross-posting to the Basex list ;-) ---------- Forwarded message --------- From: Jirka Kosek jirka(a)kosek.cz [dita-users] <dita-users(a)yahoogroups.com> Date: Mo., 22. Okt. 2018 um 21:45 Uhr Subject: [dita-users] [ANN] XML Prague 2019 - Call for Proposals To: dita-users(a)yahoogroups.com <dita-users(a)yahoogroups.com> Hello, we are glad to announce that call for proposals for XML Prague 2018 conference is open now. The XML Prague conference will include two full days of single track sessions as well as a multitrack unconference day. The conference is held on the Thursday, Friday and Saturday (February 7-9, 2019), located at the University of Economics, nam. W. Churchilla, Prague, Czech Republic. XML Prague is a conference on XML for developers, markup geeks, information managers, and students. XML Prague focuses on markup and semantic on the Web, publishing and digital books, XML technologies for Big Data and recent advances in XML technologies. The conference provides an overview of successful technologies, with a focus on real world application versus theoretical exposition. This years topics include the following: * Markup and the Extensible Web * Semantic visions and the reality * Publishing for the 21th century * XML technologies and Big Data * State of the XML Union * XML success stories Conference website: http://www.xmlprague.cz Call for proposals: http://www.xmlprague.cz/cfp/ Registration will be opened soon. Please take note of the following important ates: December 2nd – End of CFP January 9th – Notification of acceptance/rejection January 31st – Final paper (for those who will provide it) February 7-9 – XML Prague 2019 conference This year we would like to encourage new speakers -- full paper submission is no longer needed and there will be shorter slots available for those who would like to introduce/demo something "smaller". If you have any questions, interested in sponsorship or just want to make a suggestion please send email to: info(a)xmlprague.cz Jirka Kosek on behalf of XML Prague -- ------------------------------------------------------------------ Jirka Kosek e-mail: jirka(a)kosek.cz http://xmlguru.cz ------------------------------------------------------------------ Professional XML and Web consulting and training services DocBook/DITA customization, custom XSLT/XSL-FO document processing ------------------------------------------------------------------ Bringing you XML Prague conference http://xmlprague.cz ------------------------------------------------------------------

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Reflect.forName() / Performance
by Tom Rauchenwald (UNIFITS) 23 Oct '18

23 Oct '18

Hi BaseX-Team, when profiling some of our tests i found that we spend some time in Reflect.forName(). We have 2 xquery modules in the repo (we don't call java code directly). I'm not sure why BaseX tries to load our xqm as Java Modules, but what I noticed is that Reflect.forName caches the positive case (i.e., the class is found), but not the negative case (i.e., the class is not found). I've changed the code to cache the negative case as well (see below), and noticed an improvement of about 5 percent. Our tests create and query loads of small databases, so this is maybe quite an artificial speedup. I could provide a PR if this is a worthwhile improvement in your opinion (and if I'm not missing something obvious). We're still on BaseX 8.7.6 in case that matters, as far as I could see the Code didn't change in BaseX 9. Thanks, Tom Code: public static Class<?> forName(final String name) throws ClassNotFoundException { Class<?> c = CLASSES.get(name); if(c == null) { if (CLASSES.containsKey(name)) { throw new ClassNotFoundException(name); } else { try { c = Class.forName(name); } catch (ClassNotFoundException e) { CLASSES.put(name, null); throw e; } if (!Modifier.isPublic(c.getModifiers())) throw new ClassNotFoundException(name); CLASSES.put(name, c); } } return c; }

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Fairlock and query monitoring
by Maximilian Gärber 22 Oct '18

22 Oct '18

Hi, for some time now, I've switched a production system (running Basex 8.6) to FAIRLOCK = true. With PARALLEL = 16. While this helped speed up write operations, there are situations where queries go from sub-second to minute(s) if a few more users are reading/writing at the same time. The DBs in question are incrementally indexed. Since single queries are fast, I don't know what the best way of handling these situations would be. As a last resort I was thinking about adding a cache solution (write-behind) that allows for saving and delays (batches) writes. But before introducing another component to the system, I'd like to hear what other ideas might exist. Br, Max

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Optimized query for importing content based on metadata
by Jason Davis 22 Oct '18

22 Oct '18

Hi, I’ve cobbled together a query that I want to use to import xml from the filesystem into the database based on specific metadata requirements: let $xmlroot := "/Users/jason.davis/Sandbox/dita-docs/content/" for $file in file:list($xmlroot, true()) where matches($file, 'xml') or matches($file, 'ditamap') let $doc := file:resolve-path($file, $xmlroot) return if (doc($doc)//brand[contains(.,'xyz')]) then db:add("d4st^dita-docs^meta-test", $doc) else () It works, so I’m pleased! I’m just wondering if there is a more efficient way to achieve what I want to do. I know that using a specific XPath in the doc function is one thing I can do better. Any suggestions are appreciated! Thanks, Jason

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