BaseX-Talk July 2023

basex-talk@mailman.uni-konstanz.de

10 participants
15 discussions

BaseX 9.6: The Summer Edition
by Christian Grün 28 Nov '24

28 Nov '24

Dear all, We provide you with a new and fresh version of BaseX, our open source XML framework, database system and XQuery 3.1 processor: https://basex.org/ Apart from our main focus (query rewritings and optimizations), we have added the following enhancements: XQUERY: MODULES, FEATURES - Archive Module, archive:write: stream large archives to file - SQL Module: support for more SQL types - Full-Text Module, ft:thesaurus: perform Thesaurus queries - Fulltext, fuzzy search: specify Levenshtein limit - UNROLLLIMIT option: control limit for unrolling loops XQUERY: JAVA BINDINGS - Java objects of unknown type are wrapped into function items - results of constructor calls are returned as function items - the standard package "java.lang." has become optional - array arguments can be specified with the middle dot notation - conversion can be controlled with the WRAPJAVA option - better support for XQuery arrays and maps WEB APPLICATIONS - RESTXQ: Server-Timing HTTP headers are attached to the response For a more comprehensive list of added and updated features, look into our documentation (docs.basex.org) and check out the GitHub issues (github.com/BaseXdb/basex/issues). Have fun, Your BaseX Team

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recursively used variables
by Rob Stapper 12 Aug '24

12 Aug '24

Hi, The code[1] below and send as attachment generates a error message: “Static variable depends on itself: $Q{http://www.w3.org/2005/xquery-local-functions}test”. I use these variables to refer to my private functions in my modules so I can easyly refer to them in a inheritance situation. It’s not a big problem for me but I was wondering if the error-triggering is justified or that it should work. [1]=========================================== declare variable $local:test := local:test#1 ; declare %private function local:test( $i) { if ( $i > 0) then $local:test( $i - 1) } ; $local:test( 10) =========================================== Kind regards, Rob Stapper Sent from Mail for Windows 10 -- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus

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xslt:transform-report result
by Andy Bunce 11 Mar '24

11 Mar '24

Hi, Using BaseX 9.7.1 and saxon9he-9.9.1.jar The documentation suggests the ?result from xslt:transform-report should be *a* document-node where possible [1] This seems not quite to be the case when there are processing instructions or comments at the top level. In these cases a sequence of document-nodes is returned. /Andy [1] https://docs.basex.org/wiki/XSLT_Module#xslt:transform-report let $xslt:=<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" version="3.0"> <xsl:mode on-no-match="shallow-copy"/> </xsl:stylesheet> let $xml:=document{ <?something type="compact"?>, <foo/>} return xslt:transform-report($xml,$xslt) Returns map { "messages": (), "result": (<?something type="compact"?>, <foo/>) }

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Accessing BaseX server on remote machine
by Furst, Thomas 17 Aug '23

17 Aug '23

Hello, I am attempting to use BaseX from a central location on our network so that all team members can access it. I am using the Python Client to achieve this. Everything works fine when the host is entered as 'localhost'. Once I change it to the remote host name, I am getting a time out error reported back: TimeoutError: [WinError 10060] A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond On the remote machine (Windows 10 Pro for Workstations) I have opened port 1984 in the firewall on both the inbound and outbound. Can someone help me understand what I may be doing incorrectly? Or what I may have overlooked doing that is also required? Thank you, Tom Furst

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How best to cache an intermediate result in the context of a larger query?
by Eliot Kimber 10 Aug '23

10 Aug '23

In the context of a RESTXQ handler that is processing a stored document to generate HTML From it, I need to do some expensive processing and then cache the result for the next time the same document is rendered. It doesn’t make sense to preprocess all the documents to cache the data as part of my overall ingestion process because only a fraction of documents will ever be rendered by this page. I think the answer is to turn on MIXUPDATES so I can invoke an updating function in the process of the larger RESTXQ handling query, but I’m wondering if there’s some less drastic or better-architected approach? For example, should be I be invoking a separate REST end point to do the calculation, blocking on the request, and then fetch the cached result? I read through the update module and the various pages on XQuery update and feel like I still don’t quite understand what my updating options are. Thanks, Eliot _____________________________________________ Eliot Kimber Sr Staff Content Engineer O: 512 554 9368 M: 512 554 9368 servicenow.com<https://www.servicenow.com> LinkedIn<https://www.linkedin.com/company/servicenow> | Twitter<https://twitter.com/servicenow> | YouTube<https://www.youtube.com/user/servicenowinc> | Facebook<https://www.facebook.com/servicenow>

3 5

Decoding error
by Graydon Saunders 19 Jul '23

19 Jul '23

Hello -- I have some mainframe files which start off in no-known-encoding. Using Basex 10.6, I'm trying to use the bin module to make some character substitutions so the content of these files can be UTF-8. let $charMap as map(*) := map { 33: 93, (: exclamation point ! to close bracket ] :) 162: 91, (: cent-sign ¢ to open bracket [ :) 124: 33, (: pipe character | to exclamation point ! :) 160: 32, (: non-breaking space to plain space :) 26: 32 (: U+001A SUBSTITUTION CHARACTER at the end of the file; do not want :) } let $fromList as xs:integer+ := map:keys($charMap) let $fileList as xs:string+ := file:children($localPath) for $x in $fileList return (file:read-binary($x) ! bin:to-octets(.) ! (if (. = $fromList) then $charMap(.) else .) ! bin:from-octets(.) ! bin:decode-string(.,'UTF-8')) => string-join('') Four of the five sample files work; one of them returns "Decoding error: xff" If I restrict the process to the problematic file and use return (file:read-binary($x) ! bin:to-octets(.) ! (if (. = $fromList) then $charMap(.) else .)) => distinct-values() => sort() I don't find a 255 value. And I'm pretty sure all the codepoints I do have are simple, less than 255, single octet UTF-8 characters. Any suggestions for what I ought to be looking at? Thanks! Graydon -- Graydon Saunders | graydonish(a)fastmail.com Þæs oferéode, ðisses swá mæg. -- Deor ("That passed, so may this.")

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How to get stack trace from an Query Exception?
by Eliot Kimber 13 Jul '23

13 Jul '23

The docs for Try/Catch in in the XQuery_3.0 page say: · $err:additional: error stack trace However, in my testing, this only returns the place where the error was thrown, not the complete stack trace as is shown e.g., in a web app when an exception is thrown. Is it possible to get the stack trace in XQuery? I didn’t find anything searching on the BaseX-supplied DBA app. Thanks, E. _____________________________________________ Eliot Kimber Sr Staff Content Engineer O: 512 554 9368 M: 512 554 9368 servicenow.com<https://www.servicenow.com> LinkedIn<https://www.linkedin.com/company/servicenow> | Twitter<https://twitter.com/servicenow> | YouTube<https://www.youtube.com/user/servicenowinc> | Facebook<https://www.facebook.com/servicenow>

2 1

PHP Client Session Object: infinite loop in read method when bpos is null
by Tamara Marnell 13 Jul '23

13 Jul '23

Hello everyone, Once in a while, my server running BaseX will suddenly experience a big spike in write operations, the hard disk space will fill up to 100%, and the whole server will lock up. I can't say what initiates this, because the logs and metrics disprove every theory I can think of. (There's nothing unusual in the access logs or BaseX data logs, memory usage stays consistently at 45% and CPU usage at 5%, no user attempted anything like a huge bulk upload, etc.) However, one thing that always happens during these incidents is that the Apache error log blows up to a crazy size like 1 GB, filled with the message: PHP Notice: Trying to access array offset on value of type null in /[path]/client/session.php on line 164 This line is in the read method of the Session class from GitHub, and it indicates that the byte position passed to the buffer property is null. My error log probably fills up because read() is called by readString() in a while loop that never terminates. There might be extraordinary circumstances in which during construction, socket_connect returns "true" but the response is not valid or expected. -Tamara -- Tamara Marnell Program Manager, Systems Orbis Cascade Alliance (orbiscascade.org <https://www.orbiscascade.org/>) Pronouns: she/her/hers

2 5

sequences after the path operator
by Graydon Saunders 07 Jul '23

07 Jul '23

Hello -- Using BaseX 10.6, the test query let $test as xs:string := "And O Lord the pride of man, broken in the dust again" let $syntax1 as xs:string := analyze-string($test,'\p{Lu}')/(fn:match/concat('[',.,']'),fn:non-match/string()) => string-join('') let $syntax2 as xs:string := analyze-string($test,'\p{Lu}')/*/(self::fn:match/concat('[',.,']'),self::fn:non-match/string()) => string-join('') return ($syntax1,$syntax2) produces [A][O][L]nd ord the pride of man, broken in the dust again [A]nd [O] [L]ord the pride of man, broken in the dust again I'm surprised by this, because I expected document order to apply to the result of analyze-string and for syntax1 to work in the sense of having the results emerging in the same order as the input. Have I miscomprehended something? Anyone care to have a go at explaining why syntax1 doesn't maintain the order of the input? (I'm possibly mistakenly confident that I understand why syntax2 does.) Thanks! Graydon -- Graydon Saunders | graydonish(a)fastmail.com Þæs oferéode, ðisses swá mæg. -- Deor ("That passed, so may this.")

2 2

Apparent bug when setting @xml:base on element with @base
by Eliot Kimber 07 Jul '23

07 Jul '23

This XQuery demonstrates the problem: (:--------:) let $xmlBaseAtt as attribute() := attribute {'xml:base'}{'/foo/bar.xml'} let $transformed1 as element() := try { $doc1 transform with { insert node $xmlBaseAtt into .} } catch * { <error code="{$err:code}" desc="{$err:description}" object="doc1"/> } let $transformed2 as element() := try { $doc2 transform with { insert node $xmlBaseAtt into .} } catch * { <error code="{$err:code}" desc="{$err:description}" object="doc2"/> } return ( ``[No @base attribute:]`` ,$transformed1 ,``[Has @base attribute:]`` ,$transformed2 ,() ) (:--------:) The results I get with 10.6 are: No @base attribute: <root xml:base="/foo/bar.xml"/> Has @base attribute: <error code="err:XUDY0021" desc="Duplicate attribute name: xml:base." object="doc2"/> It looks like the transform processor is matching @xml:base to @base even though they are different attributes. Is this a bug or is there a different way I should be specifying the @xml:base attribute? This is an issue because @base is a DITA-defined attribute that occurs on elements on which I need to set @xml:base (which is how I found the problem). Cheers, Eliot _____________________________________________ Eliot Kimber Sr Staff Content Engineer O: 512 554 9368 M: 512 554 9368 servicenow.com<https://www.servicenow.com> LinkedIn<https://www.linkedin.com/company/servicenow> | Twitter<https://twitter.com/servicenow> | YouTube<https://www.youtube.com/user/servicenowinc> | Facebook<https://www.facebook.com/servicenow>

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BaseX-Talk July 2023