November 2022 - BaseX-Talk - mailman.uni-konstanz.de

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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Server Performance
by Johannes Bauer 01 Dec '22

01 Dec '22

Hi all, we have two Linux server VMs where our BaseX application is running - Integration - Production The used database is about 5 GB including a fulltext index and is identical on both systems. The production VM is more potent in all aspects (CPU, RAM, Disk IO, ...). Dispite all of that we do not get any significantly better performance in the production system. On top of that we even have XQuery requests that sporadically take very long (> 1 minute) that would normally take only less than one second. Again these long requests only happen in the production environment. My first assumption was that maybe it is due to additional load on the server from other sources. But that was not the case. We have the spikes even when there is no load at all. Has anyone similar experiences or any ideas what could be the cause for this behaviour? Best Regards Johannes

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right way to create a db in the middle of processing?
by Graydon Saunders 28 Nov '22

28 Nov '22

Hello -- So I've got a pattern where I want to: 1. perform some processing using proc:execute() on a directory tree of XML files (easy) 2. load the result of the processing (a parallel structure tree of XML files) into a new db (in principle, easy; db:create() does this) 3. extract information from the newly created db and write that to a file (easy) 4. use proc:execute() to run different processing on the file written in step 3 (easy, I think) 5. load the result (thankfully a single file) and process it with a query (easy, I can stuff that in a function) Ideally, this winds up as something invoked from a single query file as a sequence of functions because its eventual fate is to be part of an automated test that would ideally be a "run this one thing, look at the boolean result". I hang up on step 2; so far as I can tell, there isn't a way to say "go create a database and then make it usable to these other modules that are guaranteed not to happen until db:create() has completed" but this seems like such a common thing to want to do that I feel like I must be missing something. Thanks! Graydon

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Logging in JSON format
by Huib Verweij 28 Nov '22

28 Nov '22

Hi, from https://docs.basex.org/wiki/Logging I understand all logging in BaseX uses a fixed text format. For our Kibana/Elastic Search logging solution in OpenShift it is recommended to use JSON as the logging format. Is it possible to make BaseX generate logs in JSON format? If not, does anyone have any experience importing the BaseX logs into Kibana/Elastic Search? Hartelijke groet, Huib Verweij.

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Fulltext search with wildcards
by Johannes Bauer 23 Nov '22

23 Nov '22

Hi, I have another question regarding fulltext search performance with wildcards. Our fulltext index is rather big with 1.3 GB and about 500.000 entries. When I use the following search where there are no matches: *ft:search('db', 'CT020/.*/P', map{'wildcards':true()})* it takes about 10 seconds to get the empty result. The query requires a big amount of free memory. If I use this query here (that also has no matches): *ft:search('db', 'CT.*/20/P', map{'wildcards':true()})* it only takes about some milliseconds. Any ideas why the placement of the wildcard has such big impact on the performance? Best Regards Johannes

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Working with custom stores
by Tim Thompson 22 Nov '22

22 Nov '22

Hello, Using the store module, is it possible to read and merge multiple custom stores into main memory, or to set a particular store as context for a query? Or, do I need to serialize the stores, e.g., as JSON and then create databases for them? Thanks in advance, Tim -- Tim A. Thompson (he, him) Librarian for Applied Metadata Research www.linkedin.com/in/timathompson timothy.thompson(a)yale.edu

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Pretty print
by Giuseppe G. A. Celano 19 Nov '22

19 Nov '22

Hi, I am trying to prettyprint an XML file. I tried the serialization option “indent”=“yes”, but it does not work as expected. On BaseX 9, the prettyprint was the default setting: how to get the same result in BaseX 10 (and later)? Thanks. Best, Giuseppe

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BaseX unreachable behind load balancer
by Harry King 19 Nov '22

19 Nov '22

Hi, I’m wondering if someone might be able to offer a hint or two. I’m attempting to run BaseX in AWS behind a Network Load Balancer (NLB) using the 9.5.2 docker image with the default config to start with. I’ve setup a TCP target group and the healthcheck appears happy on port 1984.Reachability analyser suggests firewall is good to go. From the local box I can telnet localhost 1984: telnet localhost 1984 Trying 127.0.0.1... Connected to localhost. Escape character is '^]'. BaseX:3334891053316136 I get a similar response if I use the server’s private IP address: telnet 10.x.x.x 1984 Trying 10.x.x.x... Connected to 10.x.x.x. Escape character is '^]'. BaseX:3335242111998298 So far, so good. If I attempt the same via the NLB I get a timeout, which suggests to me either firewall issue or the application is refusing to listen for some reason. The documentation, seems to suggest by default, basex should respond to requests from any IP or hostname, do I understand that correctly, or do I need to alter the default config? Thanks in advance!

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