BaseX-Talk July 2019

basex-talk@mailman.uni-konstanz.de

22 participants
30 discussions

Transaction Management
by radim-havlicek＠post.cz 23 Jul '19

23 Jul '19

Hello. We use client/server architecture, especially the C# client. I read that: * Read transactions are executed in parallel. * If an updating transaction comes in, it will be queued and executed after all previous read transaction have been executed. We have a web Front-End built on BaseX. We read XML documents stored in the database, and show charts with statistics calculated from those documents. Few times per day, we copy a new document to the database (via REPLACE command to make sure, the document is not stored in the database already). The problem we are facing is that while big document is being stored to the database (10 to 20 minutes), we cannot read documents from the database and display charts for users on the web interface. The web interface is waiting until the document is stored, and then read the the needed documents, and display the charts. It is very inconvenient for users to wait so long for a chart that is normally displayed in few seconds. Is there a way we could read the xml documents from the database while another document is being stored to the database? It is very, very needed. Best regards, Radim Havlicek

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Quickest way to parse a DomSource
by Marco Lettere 22 Jul '19

22 Jul '19

Hi all, I'm currently working on the usage of BaseX Xquery scripts inside a BPMN engine. I have to access portions of the XML representation of the BPMN file by binding the engine's API. The closest that I can get to a standard XML representation is currently a javax.xml.transform.dom.DOMSource. What is the shortest way to transform (in XQuery) this DomSource to a BaseX representation of the Document in order to query it? Thanks, Marco.

2 2

PATCH verb in RestXQ implementation
by Schopper, Daniel 19 Jul '19

19 Jul '19

Dear list, I just came across the fact that BaseX does not recognize PATCH as a known HTTP verb (at least in my admittedly not bleading-edge version). Is this a feature or a bug? And, in order to work around that: is there a way of passing payload to a custom %rest:method (without having an additional PUT or POST annotation on the same XQuery function)? Thanks in advance! Best Daniel

3 4

Update operation is spawning new databases with underscore
by Zimmel, Daniel 18 Jul '19

18 Jul '19

Hi, sometimes in my update operations BaseX deliberately is spawning several databases like the following, with a name of the database plus underscore and number: DBNAME_2618234251 caused by db:replace($dbname, $dbpath|| '/' || $fname, $file-to-import, map { 'intparse': true(), 'chop': false(), 'addcache': false() }) I cannot find anything about this behavior in the docs. It seems to happen randomly, and the main database does seem ok. How can I avoid these extra databases? They will vanish only by force. BaseX 9.2.1 Thanks, Daniel

2 4

Bug in 9.2.3??
by Buddy Kresge 17 Jul '19

17 Jul '19

The below code works fine in 9.2.2 (and any version before), but when we execute the below in 9.2.3 we get the following error. Thanks in advance for your assistance. Cannot convert element() to xs:string?: $status := <EmploymentStatusCode>Active</Employment.... declare function local:employmentStatus($employee as element()?) as xs:string? { $employee/*:Employment/*:EmploymentStatus/*:EmploymentStatusCode }; declare function local:isActive($employee as element()?) as xs:boolean { let $status := local:employmentStatus($employee) return if (string-length($status) > 0) then contains($status, 'Active') else false() }; let $ee := <Subscriber><Employment><EmploymentStatus><EmploymentStatusCode>Active</EmploymentStatusCode></EmploymentStatus></Employment></Subscriber> return local:isActive($ee)

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Query filter by attributes with Colons
by Jordan Castillo 15 Jul '19

15 Jul '19

Hello BaseX Staff, I am noticing that my queries aren't working when I check the value of an attribute who has a colon in the name field. Here is an example: 1: Yields no results let $begin := db:open($documentName) return $begin//packagedElement[@name="auxiliaryResource" and @xmi:id="_12_1_8f90291_1173963323875_662612_98"] 2: Yields no results return $begin//packagedElement[@xmi:id="_12_1_8f90291_1173963323875_662612_98"] 3: Yields expected result: return $begin//packagedElement[@name="auxiliaryResource"] Example of element I am searching for here: <packagedElement xsi:type="uml:Stereotype" xmi:id="_12_1_8f90291_1173963323875_662612_98" ID="_12_1_8f90291_1173963323875_662612_98" name="auxiliaryResource"> This particular element has an "ID" attribute but most do not so checking that attribute is not an option. Any hints or tips as to how I can make this work would be greatly appreciated. Thanks! Jordan Castillo

2 1

Enforce index with dynamic values
by Beck, Julia 12 Jul '19

12 Jul '19

Hello BaseX team, I am struggeling with the enforce index pragma and get a "Improper use? Potential bug? Your feedback is welcome". So here is my feedback/question: I have XML data describing books in several databases that also contain (potentially outdated) control numbers for authority data and I have an XML doc with a list of old numbers and their replacement (== new number). So I want to go through this list and replace the old numbers in my data with the new numbers. My XQuery works for each database on its own, but as soon as I provide a list of databases, I get a NullPointerException. The xml doc with the authority numbers looks like this: <gnds> <gnd> <old>gnd_4452199-6</old>; <new>gnd_2163369-1</new>; </gnd> <gnd> <old>gnd_16288049-2</old>; <old>gnd_4683522-2</old>; <new>gnd_1901229-9</new>; </gnd> .... </gnds> The data in the databases looks like this: <rdf:RDF> <edm:ProvidedCHO @rdf:about="..."> <edm:wasPresentAt @rdf:resource="gnd_4452199-6"/> <dc:contributor @rdf:resource="gnd_4683522-2"/> ... </edm:ProvidedCHO> ... </rdf:RDF> In the XQuery, I left out the replacement part (which I thought to be the problem first, but the script already throws the error when I just want to have the new numbers printed). It works when I run it for "tmd" and "tes" individually. When I leave out the pragma it takes really long time (obviously not using the index). I more or less followed the 3rd example in http://docs.basex.org/wiki/Indexes#Enforce_Rewritings let $old_gnds := doc("oldIds.xml")/gnds/gnd, $all_db := ("tmd","tes") for $gnd in $old_gnds/old/text() let $new := $gnd/../../new/text() for $db in $all_db for $attr in db:open($db)/rdf:RDF/*/*/@rdf:resource where (# db:enforceindex #) {$attr = $gnd} return $new Best wishes, Julia -- JULIA BECK Elektronische Dienste / FIDDK Universitätsbibliothek Johann Christian Senckenberg Bockenheimer Landstraße 134-138 60325 Frankfurt am Main 069 798 39387

2 3

server load
by Ветошкин Владимир 10 Jul '19

10 Jul '19

2 4

Connecting the BaseX AppChecker to Visual Studio
by Matt Stam 09 Jul '19

09 Jul '19

Hello, I've been trying to set up and use the "AppChecker" that we are going to need to run our X++ code through. Does anyone have any knowledge on how to run this? I've followed everything laid out on their github: https://github.com/microsoft/Dynamics365FO-AppChecker. BaseX and the environmental variables are installed. But I am unsure about how to actually use it to check my code on VS. Any help would be appreciated. Best, Matt

3 2

Time complexity
by Jordan Castillo 08 Jul '19

08 Jul '19

Hello BaseX Staff, Question regarding why the time complexity of my query is dramatically different in these 2 situations. I'm building a map inside a function that is called many times, and this function receives an ID and then has to retrieve some values to store inside the map. In case #1, I check if the values exists first, otherwise I store '()': "lowerValue" : if (exists($context//packagedElement[@xmi:id=$currID]/ownedAttribute[@xmi:id=$propList[2 + $mult]]/lowerValue[@value])) then data($context//packagedElement[@xmi:id=$currID]/ownedAttribute[@xmi:id=$propList[2 + $mult]]/lowerValue/[@value]) else (), "upperValue" : if (exists($context//packagedElement[@xmi:id=$currID]/ownedAttribute[@xmi:id=$propList[2 + $mult]]/upperValue[@value])) then data($context//packagedElement[@xmi:id=$currID]/ownedAttribute[@xmi:id=$propList[2 + $mult]]/upperValue/[@value]) else () Total Time: 1526.0 In case #2:

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BaseX-Talk July 2019