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

Best methods for improving query speed with large joins
by Marko Niinimaki 21 Aug '19

21 Aug '19

Dear all, I have a database with suppliers/parts/orders/customers/listitems and I'm trying to gain performance for queries like "sum up all orders where customers are in Japan". This results to many joins of documents representing each type of entity. With a relational database I'd use foreign keys. It looks like BaseX supports DTD's. Would creating DTD's improve the query speed? In the mailing list I saw only one reference to this https://www.mail-archive.com/basex-talk@mailman.uni-konstanz.de/msg02586.ht…. In the response "a DTD-aware XQuery processor can supply the id() and idref() XPath functions. However, these do not work across documents, and the values must be legal XML identifiers. Having said that, most XML databases make indexes, so joins using FLWOR and values will work based on values." Based on that, I'd need to create a DTD for a structure that has id's and idref's and the corresponding document would be 1 GB large (to contain all the suppliers/parts/orders/customers/listitems). Would this make sense? Mark

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Built-in collations
by Zimmel, Daniel 21 Aug '19

21 Aug '19

Hi, I found out that after adding the third-party jar to the classpath as described here (http://docs.basex.org/wiki/XQuery_3.1#Collations) I can finally alphanumeric-sort my map:keys: map:keys($map_ev) => sort('http://www.w3.org/2013/collation/UCA?lang=de;numeric=yes') Which I like a lot. Are there any plans on having this already shipped with BaseX in future releases? Thanks, Daniel

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Map serialization
by Giuseppe G. A. Celano 19 Aug '19

19 Aug '19

Hi When maps are serialized, the text nodes of an element (e.g., <g>r</g>/text()) are serialized without quotes and tests with "instance-of" show that they actually are text nodes: Couldn't they be serialized with quotes? I see that with data(), the text is serialized with quotes although it is xs:untypedAtomic. Is there a reason why the text node is kept as such and, for example, no casting/atomization happens when it becomes a value in a map? Thanks. Best, Giuseppe

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Binary module
by Giuseppe G. A. Celano 14 Aug '19

14 Aug '19

Hi I am playing around with the binary module. I have two simple questions: 1) convert:string-to-base64("sàà") returns sàà : what does it mean? I see in the documentation that I need to use string() to see the value of xs:base64Binary (c8Ogw6A=), but shouldn't xs:base64Binary already be outputted as c8Ogw6A= ? (This is actually displayed in the Info Panel). 2) bin:length(convert:integers-to-base64(x)) always returns one number, no matter how big the number is. In the documentation I read that the output of bin:length should be the size of binary data in octects: how is that possible? Thanks, Giuseppe

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Declaring namespaces in xquery:eval call
by Buddy Kresge 13 Aug '19

13 Aug '19

I am trying to do something like xquery:eval("some:function()"), and when I go to execute I get "[XPST0081] No namespace declared for 'some:function' I did read the reference that was sited in your documentation for how to declare a namespace binding (http://www.jclark.com/xml/xmlns.htm) but am still having no luck Can you help me with what the map should look like given the following attempt: like xquery:eval("some:function()", map { ????? } ) Thanks in advance. Buddy Kresge

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console.log ?
by Majewski, Steven Dennis (sdm7g) 10 Aug '19

10 Aug '19

Is there an equivalent to console.log or xsl:message in XQuery or BaseX ? I know I could use the basex file: module to write to a file, but is there anything that works with the logging system to direct output according to the context ? — Steve Majewski

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Reg : ArrayIndexOutOfBoundsException
by chandra Sekhar 09 Aug '19

09 Aug '19

Dear basex team, We are getting the below error while accessing the collection. Exception ::org.basex.core.BaseXException: Improper use? Potential bug? Your feedback is welcome: Contact: basex-talk(a)mailman.uni-konstanz.de Version: BaseX 7.9 Java: Oracle Corporation, 1.7.0_151 OS: Linux, amd64 Stack Trace: java.lang.ArrayIndexOutOfBoundsException Collection size : 37 GB And did INSPECT command on the collection,It is showing success. Regards, Chandrasekhar

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Serialization mismatch using Saxon for xslt:transform
by Majewski, Steven Dennis (sdm7g) 08 Aug '19

08 Aug '19

Continuing with my test.xqm experiments… I have copied Saxon jar into WEB-INF/lib/ so xslt:transform is using Saxon. I have the following functions declared: declare %rest:path("test/xqdoc.xml") %output:method('xml') function test:doc() { inspect:xqdoc( $test:module_name ) }; declare %rest:path('test/xdoc') %output:method('html’) (: I’ve tried various values for method and html-version here ! :) %output:html-version('5.0') function test:htmldoc() { (: WTF? :) xslt:transform( test:doc(),'static/xsl/html-module.xsl', map { 'source' : 'test.xqm' }) }; Where html-module.xsl initially was: https://github.com/xquery/xquerydoc/blob/master/src/lib/html-module.xsl <https://github.com/xquery/xquerydoc/blob/master/src/lib/html-module.xsl> Accessing /basex/test/xdoc returns error message: Stopped at /usr/local/tomcat/webapps/basex/test.xqm, 41/20: [FODC0002] "" (Line 69): The entity "nbsp" was referenced, but not declared. Which was initially very puzzling, as I could not find nbsp in either my test.xqm, html-module.xsl, or inspect:xsdoc() output. Turns out, even though it was encoded as " ” in html-module.xsl, Saxon was encoding it as “ ” on output of the transform. Initially, I wasn’t sure if Saxon or BaseX was doing the serialization. I guess it seems to be both. Original output method for that stylesheet is: <xsl:output method="html" indent="yes" encoding="UTF-8"/> And changing output:method on the function to xhtml or html doesn’t have any effect on results. Changing output method on the stylesheet to xhtml causes Saxon to serialized it as “ ” instead of “ ” , and the serialization method on the basex RESTXQ function doesn’t seem to give an errors with any output methods. I take from these results that the output from Saxon xslt:transform is serialized according to the stylesheet, and then parsed again by BaseX as xml on the way to being serialized again on output from the function, and the error is coming from that implicit parse. I don’t suppose there is a way to short circuit the parsing of the xslt:transform function output and just output the results directly (?) I tried xslt:transform-text() but it escapes all of the element tags. Or a way to get it to parse the results of that transform function as html ? Clearly changing the stylesheet is the easy solution for this test file, but for some of my other real cases, I may be trying to repurpose stylesheets that will be used in different contexts: within BaseX and outside of that context, so keeping different versions of the stylesheets is going to be annoying. I suppose I could read in the stylesheets and modify the xml:output line in XQuery or XSLT before using it within BaseX. — Steve M.

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Error from function-name(request:query#0): only from RESTXQ, not REST context.
by Majewski, Steven Dennis (sdm7g) 08 Aug '19

08 Aug '19

I’ve been learning how to use the BaseX webapp, and below is one of the first test scripts for the REST interface I wrote. No problems with this script. import module namespace request = "http://exquery.org/ns/request"; declare namespace output = "http://www.w3.org/2010/xslt-xquery-serialization"; declare option output:omit-xml-declaration "no"; declare option output:method "xhtml"; (: http://docs.basex.org/wiki/XQuery_3.0#Serialization :) (: declare variable $contains := try { request:parameter( 'contains' ) } catch basex:http { '' }; Simpler to use implicit assignment: http://docs.basex.org/wiki/REST#Assigning_Variables "All query parameters that have not been processed before will be treated as variable assignments" :) declare variable $contains as xs:string external := ""; declare function local:f0line( $f ) as node() { (: build a list item with function name and function values :)I <li><b>{fn:function-name($f)}:</b> {$f()}</li> }; declare variable $CTX := try { . } catch err:XPDY0002 { () }; declare variable $DB := try { db:name( $CTX[1] ) } catch err:XPTY0004 { "" }; (: Could be, if (): [XPTY0004] node() expected, empty sequence found. but not sure if that's the only possible case. :) <html><head><title>test</title></head><body> <div id="context"> <h3>Database: { $DB }</h3> <h3>Context documents (.)</h3> <ol> { for $doc in $CTX return <li><b>{base-uri($doc)}</b></li> } </ol> </div> <div id="request"> <h3>HTTP Request</h3> <ul> { for $f in ( request:method#0, request:scheme#0, request:hostname#0, request:port#0, request:path#0, request:query#0, request:uri#0, request:context-path#0, request:address#0, request:remote-hostname#0, request:remote-address#0, request:remote-port#0 ) return local:f0line($f) } </ul> </div> <div id="params"> <h3>Request Parameters:</h3> <ul> { for $param in request:parameter-names() return <li><b>{$param}:</b> {request:parameter($param)}</li> } </ul> </div> <div id="headers"> <h3>Headers</h3> <ul> { for $header in request:header-names() return <li><b>{$header}:</b> {request:header($header)}</li> } </ul> </div> <div id="cookies" > <h3>Cookies</h3> <ul> { for $cookie in request:cookie-names() return <li><b>{$cookie}:</b> {request:cookie($cookie)}</li> } </ul> </div> <div id="xslt"> <h4>XSLT</h4> <ul> <li><b>xslt:processor: { xslt:processor()},   xslt:version: { xslt:version()}</b></li> </ul> </div> </body></html> I’m now trying to learn RESTXQ programming, so I was trying to do the same sort of thing from a RESTXQ module. I was getting an error from the line where (: request:query#0, :) is now commented out, and added the line: <li>{ request:query( ), function-name(request:query#0)}</li> And I see that what happens is that it’s the latter function-name(request:query#0) that is generating an error, but only when there is no query string in my request. An empty query string, i.e. “http://localhost/basex/test? <http://localhost/basex/test?>” , for example, works. But “http://localhost/basex/test <http://localhost/basex/test> returns: Stopped at /usr/local/tomcat/webapps/basex/test.xqm, 33/66: [XPTY0004] Cannot convert empty-sequence() to xs:string: (). I assume this has something to do with how RESTXQ processes form and request parameters, and I probably don’t actually need to do it this way, but I was wondering what exactly is the source of the problem with doing something like this or if there is an obvious work around. Maybe writing another local function to wrap around request:query and to use in that loop. ( One reason I chose that test to convert to RESTXQ was that it wasn’t obvious to be from the docs if I could mix those different access methods, and so what was surprising was that it mostly worked — only that one function failed (so far)). module namespace test = 'http://localhost/test'; import module namespace request = "http://exquery.org/ns/request"; declare function test:f0line( $f ) as node() { (: build a list item with function name and function values :) <li><b>{fn:function-name($f)}:</b> {$f()}</li> }; (:~ : Generates a welcome page. : @return HTML page :) declare %rest:path("test") %output:method("xhtml") %output:omit-xml-declaration("no") %output:doctype-public("-//W3C//DTD XHTML 1.0 Transitional//EN") %output:doctype-system("http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd") function test:test( ) as element(Q{http://www.w3.org/1999/xhtml}html) { <html xmlns="http://www.w3.org/1999/xhtml"> <head> <title>BaseX HTTP Services</title> <link rel="stylesheet" type="text/css" href="static/style.css"/> </head> <body> <div class="right"><a href='/'><img src="static/basex.svg"/></a></div> <h1>TEST</h1> <div id="debug" > <ul> <li>{ request:query( ), function-name(request:query#0)}</li> </ul> </div> <div id="request"> <h3>HTTP Request</h3> <ul> { for $f in ( request:method#0, request:scheme#0, request:hostname#0, request:port#0, request:path#0, (: request:query#0, :) request:uri#0, request:context-path#0, request:address#0, request:remote-hostname#0, request:remote-address#0, request:remote-port#0 ) return test:f0line($f) } </ul> </div> </body> </html> };

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comment()
by Marc 08 Aug '19

08 Aug '19

Hi, I want to write a comment in the xml I produce with my XQuery. I try to use the comment() function, but each time I want to put something inside the () i have a syntax error. for example : <test> {comment("test"), let $r := random:integer(100) + 1 for $j in (/*)[$r] return ( $r,$j) } </test> or (who is more what I want to do) <test> { let $r := random:integer(100) + 1 for $j in (/*)[$r] return (comment("$r"),$j) } </test> I don't find any example on how to use the comment function. Anyone have example about that use? Thanks Marc

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