May 2015 - BaseX-Talk - mailman.uni-konstanz.de

A very short question about BaseX
by Fabrizio Venerandi 08 May '15

08 May '15

Hi, I’m testing BaseX and I have a very short question about XQuery Update Facility. If I try in other XQuery processor like Saxon a simple query that add a ‘id’ in XML, like this: xquery version "1.0"; declare default element namespace "http://www.w3.org/1999/xhtml"; let $sourcedoc := fn:doc("MOST.xhtml") return for $ancora at $gatto in $sourcedoc//*[@class="testo"] return if (not($ancora/@id)) then insert node attribute id {concat("testo",$gatto)} into $ancora else() Saxon run the Query and change the original file, “MOST.xhtml”. If I try the same query in XBase on Ubuntu, I see in the log XBase find the tag to add the id, but the original file is not changed. What I’m missing? Thank you Fabrizio

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Performance issue related with Casting.
by ankit kumar 08 May '15

08 May '15

Hi, I am invoking a java method inside My XQuery script, My java methods returns a string array which contains the Id of elements. Now I am taking that list in a xquery variable. It looks like this. let $ids := javacontext:getIds(); // Java Method return /sample_xml/category/product[@id = $ids] Now the problem is that, It is working fine with this, but when I declare variable $ids as xs:string* sequence. It performance is decreased by almost 100%. It looks like this. let $ids as xs:string* := javacontext:getIds(); // Java Method return /sample_xml/category/product[@id = $ids] But, for bigger no of products, and ids . when the variable $ids declared as xs:string*, it is working good, but when I removed xs:string*. it performance decreased drammatically. I have no idea, why it is working in such a way. Any kind of help is appreciated. Thanks, Ankit

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xquery of attributes
by Florent Gallaire 07 May '15

07 May '15

In the RESTXQ documentation there is this example which works fine : declare %rest:path("cities") %output:method("json") %output:json("format=jsonml") function page:cities() { element cities { db:open('factbook')//city/name } }; If I have the same factbook db but with name as attribute and not as element, with the only change in the code the xquery request db:open('factbook')//city/@name I will have the error message: [XQDY0025] Duplicate attribute 'name'. That's ok, but what is the right way in xquery to easily use multiple attributes as return value of request. Is the right way to prefer elements to attributes ? Cheers Florent -- FLOSS Engineer & Lawyer

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debugging
by Rob Stapper 06 May '15

06 May '15

Hi, For those who, like myself, loose themselves often in their code, hereby a little debug-facility. Nothing much but it helps me keep track of my code. To get an idea of the debug-output, have a look at the attached output-file. Unfortunately the code isn't integrated in the BaseX-core, but it's just an xquery-module. So you, unfortunately, do have to write a few debug-calls in your, probably already buggy, code. On the other hand it's pretty straight forward; see attachment "debug_demo.xq" for usage. Hopes this can be of use for somebody. Rob Stapper. Ps. Improvements are very welcome. --- Dit e-mailbericht is gecontroleerd op virussen met Avast antivirussoftware. http://www.avast.com

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Running commands on BaseX on Tomcat
by Kristian Kankainen 06 May '15

06 May '15

Hello! I have BaseX 8.11 running on Tomcat and need to execute some commands or XQuery for deploying xml files from elsewhere. I allready have a XQuery function for this and can do it on my local setup using for example the basexclient. My problem is that the Tomcat is available only through HTTP and I wouldn't like to open up the function for the outside world using RESTXQ. Is there a way to "talk" with the BaseX in the Tomcat? I have full access to the machine via SSH. Another way I thought of would be to just upload the data folder from my local setup, but it doesn't feel the right way to do it. Best regards Kristian K

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Base-X basics :-}
by Niels Grundtvig Nielsen 06 May '15

06 May '15

I've used ColdFusion and (reluctantly) php with MySQL, so I have some idea about combining database query with html tags to get formatted output … but I'd welcome a pointer to a tutorial about doing the same thing with Base-X Also, what would you recommend as an introduction to xQuery? w3schools … I seem to remember this was a bit brief, and this afternoon I can't get it to load anyway; wikiBooks on xQuery already incudes exist-DB specific code in the second of its "Beginning examples". Thanks in advance!

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Re: [basex-talk] Pulling files from multiple zips into one DB
by Fabrice Etanchaud 04 May '15

04 May '15

Dear Constantine, In my experience, commands are always faster than db:* calls. Maybe someone @basex could confirm that, and that commands do not use the Pending Update List ? Are you sure you disabled ADDRAW ? If there are many raw files along the xml files, you may have better results extracting and rearchiving only xml before. I have the same problem with patent archives, where each xml file may come with many pdf and gif. Best regards, Fabrice De : Hondros, Constantine (ELS-AMS) [mailto:C.Hondros@elsevier.com] Envoyé : lundi 4 mai 2015 14:01 À : Fabrice Etanchaud Objet : RE: Pulling files from multiple zips into one DB Is that going to be any faster do you think? I tried it and it took a looooong time to read through the zips, so I am hoping there might be a faster more direct way of doing it. From: Fabrice Etanchaud [mailto:fetanchaud@questel.com] Sent: 04 May 2015 13:56 To: Hondros, Constantine (ELS-AMS) Subject: RE: Pulling files from multiple zips into one DB Hello Constantine, Why don't you simply create a new collection with ADDARCHIVES=true ? Best regards, Fabrice De : basex-talk-bounces(a)mailman.uni-konstanz.de<mailto:basex-talk-bounces@mailman.uni-konstanz.de> [mailto:basex-talk-bounces@mailman.uni-konstanz.de] De la part de Hondros, Constantine (ELS-AMS) Envoyé : lundi 4 mai 2015 13:50 À : basex-talk(a)mailman.uni-konstanz.de<mailto:basex-talk@mailman.uni-konstanz.de> Objet : [basex-talk] Pulling files from multiple zips into one DB Hello all, I need to merge any XML files located in 500 GB of zips into a single DB for further analysis. Is there any faster or more efficient way to do it in BaseX than this? TIA. for $zip in file:list($src, false(), '*.zip') let $arch := file:read-binary(concat($src, '\', $zip)) for $a in archive:entries($arch)[ends-with(., 'xml')] return db:add('my_db', archive:extract-text($arch, $a), $a) TIA, Constantine ________________________________ Elsevier B.V. Registered Office: Radarweg 29, 1043 NX Amsterdam, The Netherlands, Registration No. 33156677, Registered in The Netherlands. ________________________________ Elsevier B.V. Registered Office: Radarweg 29, 1043 NX Amsterdam, The Netherlands, Registration No. 33156677, Registered in The Netherlands.

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Pulling files from multiple zips into one DB
by Hondros, Constantine (ELS-AMS) 04 May '15

04 May '15

Hello all, I need to merge any XML files located in 500 GB of zips into a single DB for further analysis. Is there any faster or more efficient way to do it in BaseX than this? TIA. for $zip in file:list($src, false(), '*.zip') let $arch := file:read-binary(concat($src, '\', $zip)) for $a in archive:entries($arch)[ends-with(., 'xml')] return db:add('my_db', archive:extract-text($arch, $a), $a) TIA, Constantine ________________________________ Elsevier B.V. Registered Office: Radarweg 29, 1043 NX Amsterdam, The Netherlands, Registration No. 33156677, Registered in The Netherlands.

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Querying a subset
by Menashè Eliezer 04 May '15

04 May '15

Hello, I'm using Java org.xmldb.api package for accessing the Basex server (xmldb:basex://...) After getting the resultSet I need to make further queries about the requested subset (for reporting, etc.) I have seen that getId() cannot be used since the Resource will be anonymous if it is obtained as the result of a query. Source: http://xmldb-org.sourceforge.net/xapi/api/index.html The queries are not fixed and are based on end user selection. I couldn't find a way to have a direct access/reference to a document. In my case the ID is simply the filename, but it doesn't seem to be so efficient. I wonder if creating a temporal collection for the subset would be faster than making query/queries similar to the following example in which there are only two ids, but I can have thousands of them: let $ids := ('360836','300139') for $x in collection("collection_name") let $filename := substring-after(base-uri($x),'/') let $id := substring-before($filename,'.') where $id = $ids return ... -- With kind regards, Menashè

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Poor runtime performance of node insertion in BaseX 8.1.1 (compared to BaseX 7.6)
by Werner Dworaczek 03 May '15

03 May '15

Hi Christian, I have found that BaseX 8.1.1 has a very poor performance in comparison to BaseX 7.6 regarding inserting XML elements into an XML document. In my application I very often add new data to the DB by using a construct like this insert node local:recordsWithObjectType(‚Type') into /rootDoc local:recordsWithObjectType() is an xQuery function returning typically several thousand XML nodes which has to be inserted info a given root document. Running this kind of stuff on BaseX 7.6 I typically have a runtime of 500 ms when adding round about 3.000 nodes. Running the exact same stuff on BaseX 8.1.1 (same data) the runtime is about 5.000 ms (factor 10 more). Is there a way to boost the insert performance in BaseX 8.1.1 to a value comparable to BaseX 7.6? Thanks in advance, Werner

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