BaseX-Talk April 2023

basex-talk@mailman.uni-konstanz.de

21 participants
21 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

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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/>) }

3 7

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

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BaseX and Fedora 38
by Ben Engbers 28 Apr '23

28 Apr '23

Hi, Today I upgraded my PC to linux Fedora 38. The only problem I encountered is that when trying to start basexgui, my session logs off. I can start the server and the RbaseX-client works well so it probably is only the GUI that's giving problems. Is it possible to see what's causing the failure? Ben Engbers

3 4

JSON serialization
by Giuseppe G. A. Celano 27 Apr '23

27 Apr '23

Hi all! I have a few XML documents, whose content I would also like to provide in JSON. The XML files contain many strings encoded within comments, such as <!--incipit—>, and I would like to transfer such string contents unchanged into JSON. However, I am having a hard time to deal with “-” ( using data(<!---—>) ), which is rendered as “&45;” , and “>”, which is translated into “>”: I tried a lot, but nothing seems to work: is there a way to keep “-” and “>” unchanged while serializing to JSON? Another issue I am experiencing is that, after JSON serialization, the order of the key-values in a map does not follow that specified in my code: I know that the order is not computationally meaningful, but for reading purposes it would make a huge difference in my case, because one key contains a long array of objects and therefore I would like the keys with shorter contents to be serialized before. Ciao, Giuseppe

2 5

Binding multiple items to 1 variable (server protocol)
by Ben Engbers 27 Apr '23

27 Apr '23

Hi, My ultimate goal is to investigate, using a SWI-Prolog client and Basex, whether a combined use of Prolog and XQuery offers advantages. To write a Prolog client, I first had to learn C++ and the spin-off from that is that I am now almost done writing a C++ client. As with writing the R client at the time, I have questions when applying the 'Bind' command. The server protocol contains the following sentence: "the two items xs:integer(123) and xs:string('ABC') are encoded as 123, \02, xs:integer, \01, ABC, \02, xs:string and \00" Does this mean that multiple items of different types can be bound to one (1) {name} variable? If so, in what situation could this be applied? Where can I find an example FLWOR query that uses this? Ben Engbers

1 0

Geo module removal on version 10 or above
by 13519004 Muhammad Bintang Pananjung 26 Apr '23

26 Apr '23

Hi all, Currently, i'm implementing spatial module on XML databases for my final project. i wonder why was geo module is removed on version 10 or above? i can't find any explanation about it in the documentation. thank you

3 2

skipping empty cells when parsing CSV
by Ron Van den Branden 26 Apr '23

26 Apr '23

Hi all, I'm investigating a way of analysing a massive set of > 900.000 CSV files, for which the CSV parsing in BaseX seems very useful, producing a db nicely filled with documents such as: <csv> <record> <ResourceID>00003a92-d10e-585e-84a7-29ad17c5799f</ResourceID> <source.id>bbcy:vev:6860</source.id> <card>AA</card> <order>0</order> <source_field/> <source_code/> <Annotation>some remarks</Annotation> <Annotation_Language>en</Annotation_Language> <Annotation_Type/> <resource_model/>  </record> <record> <ResourceID>00003a92-d10e-585e-84a7-29ad17c5799f</ResourceID> <source.id>bbcy:vev:6860</source.id> <card>BE</card> <order>0</order> <source_field/> <source_code>concept</source_code> <Annotation/> <Annotation_Language/> <Annotation_Type/> <resource_model/>  </record>  </csv> Yet, when querying those documents, I'm noticing how just selecting non-empty elements is very slow. For example: //source_code[normalize-space()] ...can take over 40 seconds. Since I don't have control over the source data, it would be really great if empty cells could be skipped when parsing CSV files. Of course this could be a trivial post-processing step via XSLT / XQuery, but that's unfeasible for that mass of data. Does BaseX provide a way of telling the CSV parser to skip empty cells? Best, Ron

2 5

Odd behaviour in the GUI (XPath with XQuery window)
by Zimmel, Daniel 19 Apr '23

19 Apr '23

Hi, somewhere between BaseX 9 and 10 there was a change in the behaviour of the Find/XQuery window (which I use quite a lot for quick access to data): * with 9.5, I can enter any valid XPath, and then delete it for a fresh start with another expression... * with 10.3, whenever I do the following: * place the cursor in the XQuery window * hit Strg-A to mark the line so I can start with a new query * enter a slash to my XPath, it jumps back to a random entry in the history, and does appends my slash to that entry. This does not make sense to me at all. Is this a feature or a bug? Am I using it wrong? I find it quite irritating, because it takes away the possibility to fire a quick XPath (as a valid XQuery expression) on the currently opened database without having to open a fresh query tab. Sorry if i am missing something obvious. Thanks, Daniel

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BaseX-Talk April 2023