BaseX-Talk March 2024

basex-talk@mailman.uni-konstanz.de

11 participants
14 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

11 43

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

4 7

hof:until is gone?
by Graydon Saunders 28 Mar '24

28 Mar '24

Hello -- So I'm trying to do this: import module namespace xcs = "http://www.xcential.com/xquery/utils/script" at "same-words-same-order-script.xqm"; (: we don't need xc computationally but there are external variables in that namespace in scope :) import module namespace xc = "http://www.xcential.com/xquery/utils" at 'same-words-same-order.xqm'; declare function xc:dropTableLines($in as node()*,$toggle as xs:boolean) as node()* { switch (true()) case empty($in) return () case starts-with(head($in),':stab') return (<line/>,xc:dropTableLines(tail($in),true())) case starts-with(head($in),':rtab') return (<line/>,xc:dropTableLines(tail($in),false())) case $toggle return (<line/>,xc:dropTableLines(tail($in),$toggle)) default return (head($in),xc:dropTableLines(tail($in),$toggle)) }; let $test as element() := <text> <line></line> <line></line> <line>:stab</line> <line>weasels</line> <line>:stab</line> <line>weasels</line> <line></line> <line></line> <line>:rtab.</line> <line></line> <line>asparagus</line> <line></line> <line></line> <line>:stab</line> <line></line> <line>weasels</line> <line>:rtab.</line> <line>asparagus</line> <line>asparagus</line> <line>asparagus</line> <line>asparagus</line> <line>asparagus</line> <line>:stab</line> <line>:stab</line> <line></line> <line></line> <line>:stab</line> <line></line> <line>weasels</line> <line></line> <line>:rtab.</line> <line></line> <line>asparagus</line> <line></line> <line></line> <line></line> </text> return element {'text'} { xc:dropTableLines($test/line,false()) } Only at scale the stack blows up and I get the "try tail recursion?" suggestion. I would have tried hof:until for that, since I have to pass the current state of "are we dropping or not dropping intervening content?", but it looks like it's been removed? And the available hof functions in 4 look like they're strictly positional which is actively unhelpful in this case. (At least with whatever brain cells I currently have.) What's the appropriate pattern for "process a sequence, toggling an action on or off based on the last member of the sequence we looked at?" Thanks! Graydon

6 8

error Access Denied
by Synnott, Stephane 28 Mar '24

28 Mar '24

Hi, I have a C# .net application on my local machine, I have started the BaseX server and I want to use BaseX in my .Net application but as soon as I want to create a Session: Session session = new Session("localhost", 1984, "admin", "admin"); I also tried with no username and password but it is the same result. I get an "Access Denied". What am I missing? Thanks in advance, Stephane ________________________________ IMPORTANT NOTICE: This message may contain confidential or privileged information and is intended only for the individual named. If you are not the intended recipient you should not disseminate, distribute or copy this email. Please notify the sender immediately if you have received this email by mistake and delete it from your system. AVIS IMPORTANT: Le pr?sent courriel peut contenir des renseignements confidentiels ou privil?gi?s et est strictement r?serv? ? l'usage du destinataire pr?vu. Si vous n'?tes pas le destinataire pr?vu, vous ne devez pas diffuser, distribuer ou copier ce courriel. Veuillez aviser imm?diatement l'exp?diteur si vous avez re?u ce courriel par erreur et supprimez-le de votre syst?me. ________________________________

2 2

BaseX and NFS
by Marco Lettere 20 Mar '24

20 Mar '24

Dear all, we have an instance of BaseX running on top of an NFS exported disk. Yes yes I know it's not the best possible scenario thus I was expecting a slight performance decrease. Anyway, when comparing local disk to NFS disk, for a tiny operation like storing a very small document into a database (without optimize or indexes) we get orders of magnitude of difference. And I'm saying from few hundreds of ms to several seconds in some cases. Does anyone have experience with cases like these? Or a solid motivation that explains this degradation? Thank you very much as usual. Marco.

2 1

Out of Main Memory
by Murray, Gregory 15 Mar '24

15 Mar '24

Hello, I’m working with a database that has a full-text index. I have found that if I iteratively add XML documents, then optimize, add more documents, optimize again, and so on, eventually the “optimize” command will fail with “Out of Main Memory.” I edited the basex startup script to change the memory allocation from -Xmx2g to -Xmx12g. My computer has 16 GB of memory, but of course the OS uses up some of it. I have found that if I exit memory-hungry programs (web browser, Oxygen), start basex, and then run the “optimize” command, I still get “Out of Main Memory.” I’m wondering if there are any known workarounds or strategies for this situation. If I understand the documentation about indexes correctly, index data is periodically written to disk during optimization. Does this mean that running optimize again will pick up where the previous attempt left off, such that running optimize repeatedly will eventually succeed? Thanks, Greg Gregory Murray Director of Digital Initiatives Wright Library Princeton Theological Seminary

4 8

validate:xsd() questions
by Murray, Gregory 11 Mar '24

11 Mar '24

Hello, What is the default value of the “cache” option for the validate:xsd() function? The default doesn’t seem to be indicated in the documentation for that function. Also, the following code raises an error message saying “Item expected, empty sequence found” but that seems odd since the second argument to validate:xsd() is supposed to be optional, thereby telling the validation process to fall back to using the schema indicated in the document itself. let $options := map {'cache' : true()} for $doc in collection() return validate:xsd($doc, (), $options) Is this a bug or have I misunderstood something? Thanks, Greg Gregory Murray Director of Digital Initiatives Wright Library Princeton Theological Seminary

2 1

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/>) }

3 7

Troubles with ft:mark
by Jack Steyn 07 Mar '24

07 Mar '24

Hi BaseXers, Consider the following query run on a database 'factbook' containing factbook.xml with full-text indexing: declare function local:search( $database as xs:string, $query as xs:string ) { let $country-search := ft:search($database, $query)/ancestor::country let $city-search := ft:search($database, $query)/ancestor::city/ancestor::country let $other-search := ft:search($database, $query)/parent::*[name() = ('ethnicgroups', 'languages')]/ancestor::country let $country-mark := $country-search[.//name[text() contains text { $query }]] => ft:mark() let $city-mark := $city-search[.//city[text() contains text { $query }]] => ft:mark() let $other-mark := $other-search[.//*[name() = ('ethnicgroups', 'languages')][text() contains text { $query }]] => ft:mark() return ( $country-mark, $city-mark, $other-mark ) }; local:search('factbook', 'German') The first result of this query is the entry for Austria. I would expect both of the instances of the word 'German' in that entry to be surrounded by <mark> tags. However only the first instance is. Some changes that produce the correct result for the Austria entry: - replacing $database with 'factbook' in the definition of $other-search, or - deleting either $country-mark or $city-mark in the sequence returned. If you make either of the above changes, but additionally change the predicate [text() contains text { $query }] to [ft:contains(text(), $query)], the incorrect result returns. Any idea what might be causing this? I'm running BaseX 10.7. Cheers, Jack

2 5

Inconsistent behavior for root context in BaseX GUI
by Thompson, Timothy 06 Mar '24

06 Mar '24

I’ve been noticing an inconsistent behavior in the GUI with BaseX 11 beta (build 17d8426). I have a simple query on a database created from a CSV file. Sometimes it works, but sometimes the root context is evaluated as an empty sequence: - rewrite context value: . -> () - rewrite util:root(nodes): util:root(()) -> () I notice this when I open the database as context and try to execute the query. After the query fails, if I try to click on the “home” icon in the result panel, it also returns an empty sequence, even though the database is open. If I reopen the database and run the query, it works again. Sample data: <csv> <record> <entry>http://id.loc.gov/authorities/names/n00000121</entry<http://id.loc.gov/authorities/names/n00000121%3c/entry>> <entry>http://id.loc.gov/rwo/agents/n00000121</entry<http://id.loc.gov/rwo/agents/n00000121%3c/entry>> <entry>0.11861849</entry> </record> <record> <entry>http://id.loc.gov/authorities/names/n00000122</entry<http://id.loc.gov/authorities/names/n00000122%3c/entry>> <entry>http://id.loc.gov/rwo/agents/n00000122</entry<http://id.loc.gov/rwo/agents/n00000122%3c/entry>> <entry>0.11699477</entry> </record> <record> <entry>http://id.loc.gov/authorities/names/n00000267</entry<http://id.loc.gov/authorities/names/n00000267%3c/entry>> <entry>http://id.loc.gov/rwo/agents/n00000267</entry<http://id.loc.gov/rwo/agents/n00000267%3c/entry>> <entry>0.10811427</entry> </record> </csv> Query (with DB open as context): count(distinct-values( for $rec in /csv/record where contains($rec/entry[1], "id.loc.gov") return $rec/entry[1] )) Thanks in advance, Tim -- Tim A. Thompson (he, him) Librarian for Applied Metadata Research Yale University Library www.linkedin.com/in/timathompson<http://www.linkedin.com/in/timathompson>

2 3

2025

2024

2023

2022

2021

2020

2019

2018

2017

2016

2015

2014

2013

2012

2011

2010

BaseX-Talk March 2024