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

Performance tuning
by Csaba Fekete 27 Feb '25

27 Feb '25

Hi I have a web server that runs Basex 11.1. The server is a VPS with 18G of RAM. I have a directory of documents in various sizes, ranging from a few kilobytes up to 2G. I am trying to import these documents with the command CREATE DB mydb /path/to/docs With the default jvm max heap size (2GB) I get the error: Out of main memory If I raise the max heap size to 4GB, I get the same error. If I raise it to 8GB, the system becomes unresponsive. How can I determine how much system memory I need to be able to carry out this task? Thanks

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RESTXQ Textarea request paramater
by brian＠kennison.name 27 Feb '25

27 Feb '25

Everyone, I’m trying to build a comment form using RESTXQ that has a texarea element. I was hoping to use the new lines from the textarea for simple formatting but when the form is submitted the request parameter is striped of all the linefeeds ( it looks like normalized text). Is this the expected behavior? Thanks — Brian

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Editor format adjustments
by Joel Kalvesmaki 24 Feb '25

24 Feb '25

Hi everyone, I just joined. BaseX is awesome (as y'all know). I like CTRL+SHIFT+F for formatting, but it is also messing up string values, which especially wreaks havoc with regular expressions. That is... let $regex := "(a|z)" ...becomes... let $regex := "( a|z )" I didn't see anything in the documentation or archives about micromanaging the formatting. Is the best practice to avoid formatting altogether? Or is there a hidden pragma to exempt lines from being formatted? Joel -- Joel Kalvesmaki Director, Text Alignment Network http://textalign.net

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Re: Synchronizing access to store
by Andy Bunce 24 Feb '25

24 Feb '25

>so if you call store:get, store:put or store:write in the first process, a second process will not wait until the store operations are completed. In non XQuery contexts a semaphore [1] might be used to ensure that my other threads don't get between a get and put. In the spirit of blurring the XQuery Java boundaries I tried [2]. It seems to work. Is it dangerous? [1] https://docs.oracle.com/javase/8/docs/api/java/util/concurrent/Semaphore.ht… [2] declare namespace Semphore ="java:java.util.concurrent.Semaphore"; declare function local:config-update($k as xs:string,$v as item(),$sem) { Semphore:acquire($sem), try{ let $u:=store:get("config")=> map:put($k, $v) return store:put("config",$u) }catch * { trace("Errrr",$err:description) } ,Semphore:release($sem) }; let $sem:=Semphore:new(1,true()) let $s1 := store:put("config", map{}) let $s2 := xquery:fork-join( for $i in (1 to 100) return function(){ let $r:=(prof:sleep(10),$i) return local:config-update( string($i),$r,$sem) } ) return count(map:keys(store:get("config"))) On Tue, 28 Jan 2025 at 14:09, Marco Lettere <m.lettere(a)gmail.com> wrote: > Ok, thanks for the clarification. > > M. > On 28/01/25 15:08, Christian Grün wrote: > > Sorry Christian, do you mean *not* synchronized? >> > With »synchronized«, I meant to refer to a lower level: You will not end > up with a corrupt key/value store or with I/O conflicts when accessing and > updating the store via multiple threads. However, as you have already > observed, multiple operations are not executed in a well-defined order, so > if you call store:get, store:put or store:write in the first process, a > second process will not wait until the store operations are completed. > >

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where instead of when in window start clause
by Martin Honnen 22 Feb '25

22 Feb '25

I mistyped a start clause in a tumbling window expression using "where" instead of "when" for tumbling window $w in (1 to 20) start at $s where $s mod 3 = 1 return <window>{$w}</window> see https://fiddle.basex.org/?share=%28%27query%21%27for+tumbling+-*w+in+%7B1+t…, but I didn't get an error but a result <window>1</window> <window>4</window> <window>7</window> <window>10</window> <window>13</window> <window>16</window> <window>19</window> Shouldn't that query give a syntax error that "when" is expected instead of "where"? Or is that a new XQuery 4 feature that the "when" clause can be omitted and the above is kind of parsed/executed as for tumbling window $w in (1 to 20) start at $s where $s mod 3 = 1 return <window>{$w}</window> ?

2 1

Install on windows fails because of JAVA_TOOL_OPTIONS
by Peter Boot 22 Feb '25

22 Feb '25

Hello, I tried to install BaseX on Windows 11 and it kept giving me the message that Java 11 was needed, even though I already was at 20 and now am at 21. Then I noticed that java --version also reported a JAVA_TOOLS_OPTIONS environment variable: java --version Picked up JAVA_TOOL_OPTIONS: -Dfile.encoding=UTF-8 openjdk 21.0.6 2025-01-21 LTS OpenJDK Runtime Environment Temurin-21.0.6+7 (build 21.0.6+7-LTS) OpenJDK 64-Bit Server VM Temurin-21.0.6+7 (build 21.0.6+7-LTS, mixed mode, sharing) After removing that variable it no longer appears in the output of the version command and the install runs fine. I suppose it messes up parsing the version output. Peter

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Need confirmation on http:send-request
by Marco Lettere 13 Feb '25

13 Feb '25

Dear Christian et al, moving to basex 11.7 today I've found out that it is not necessary to serialize the body content in an http-request such as [1]. If I do (as I had to up to Basex 10.7) the body is no longer understood. Now I obtsain correct behaviour when using code as in [2]. Can you confirm this change in behaviour? And if yes, this has a huge impact on the many many http calls we have so maybe it should be documented? Thanks a lot as usual! M. [1] let $body := json:serialize(<json type="object"/>) return <http:request href="url" method="POST"> <http:body media-type="application/json">{$body}</http:body> </http:request> [2] let $body := <json type="object"/> return <http:request href="url" method="POST"> <http:body media-type="application/json">{$body}</http:body> </http:request>

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None
by None 28 Jan '25

28 Jan '25

people (there is some reason why no other XQuery processor chose this solution =96 and why so many mailing list entries from implementations other than BaseX focus so much an namespaces..). Some more introductory details on various namespace intricacies, and the discussion around it, are e.g. found at: http://www.jclark.com/xml/xmlns.htm http://www.stylusstudio.com/xmldev/201004/bythread.html Christian

1 0

None
by None 28 Jan '25

28 Jan '25

dropped and synthetically generated during the serialization process; and that our implementation would look much cleaner.

1 0

None
by None 28 Jan '25

28 Jan '25

BaseX's behavior is somehow influenced by whether a document uses namespaces or not? Is that true? In other words, BaseX shows different performance depending on whether prefixes are used? Why is that so? Why did you not choose a representation that abstracts away namespace prefixes and treats all elements as if they were in a namespace? Logically, it's not a higher burden (storing a pair (index, string) is just as efficient as storing or indexing a string); and BaseX is not required to output XML that preserves prefixes and default namespaces when a query is made; any equivalent XML that expresses the query result is acceptable. I'm wondering if the correctness problems we're seeing with respect to namespaces may be due to this decision of treating namespaces specially rather than the default case. - Godmar

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