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

basex, nfs, and local storage
by Baysdon, Joseph 24 Jan '17

24 Jan '17

My baseX database is accessed via an NFS mount, and I’d like to improve its performance by moving its re-creatable files (e.g. indices) to a local disk. For the sake of NFS backup & restore, I’d like to keep the db files which cannot be re-created on the NFS servers. Would someone please identify which db files I can move to a local disk, and which files cannot be re-created and therefore, must remain on NFS? Thanks, Joe

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RestXQ returning JSON
by Marco Lettere 24 Jan '17

24 Jan '17

Hello all, this morning just stumbled into this issue and I'm wondering whether it could be somehow smoothed up ... I have the following RestXQ function: declare %rest:path("/f") %rest:GET %output:method("json") function a:f() { (:code ...:) }; 1) Replacing comment with the following code correctly returns an empty object: let $out := (<json type="object"></json>) return $out 2) Replacing comment with the following code correctly returns an expected exception (" [SERE0023] Only one item can be serialized with JSON." : let $out := (<json type="object"></json>, <json type="object"></json>) return $out 3) Replacing comment with the following code returns a somewhat less expected Null-pointer exception : let $out := (<json type="object"></json>, <json type="object"></json>) return array{$out} 4) In order to get the expected Json array I need to write the code like the following: let $out := (<json type="object"></json>, <json type="object"></json>) return array{ $out ! json:parse(json:serialize(.), map{ "format" : "map"}) } I'm not sure whether the array could be inferred from the sequence directly in a pattern like 2. But I would expect that 3) should work. Isn't it? Thanks for any explanation. Regards, Marco.

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Progress monitoring of XML import
by Shaun Flynn 23 Jan '17

23 Jan '17

Hello there, I am writing an application using JavaFx 8. A facility I would like to have is a progress bar showing how the db:add command is running, similar to what the Basex GUI shows when creating a new database. Is it possible to send updates from BaseX to another application? Shaun

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Losing some space entities
by France Baril 20 Jan '17

20 Jan '17

Hi, When I serialize content to HTML5, I lose some entities. xquery: adds '‍' in front of some content and outputs html html: should have '&zwj;', but doesn't. I've tried with 8204 and even the half space 8201. The only special space that seems to work is  , but it won't do for what I need right now. Code sample: *let* *$target-table* := *copy* *$copy* := *$base-table* *modify*( *for **$td* *in **$copy*//*tr*/*td*[*position*()= *$column-to-filter-by*] *let* *$new-value* := ('‍', *for **$node* *in **$td*/*node*() *return **$node*) *return replace* *value* *of* *node* *$td* *with **$new-value* ) *return **$copy* *return * *$target-table* Is there any way to solve this? -- France Baril Architecte documentaire / Documentation architect france.baril(a)architextus.com

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fn:unparsed-text fails in command line XQuery
by Gunther Rademacher 20 Jan '17

20 Jan '17

Hello list, I have a file some.xml containing <xml>hello world!</xml> and I can read it in BaseX code like this: java org.basex.BaseX "declare namespace fn='http://www.w3.org/2005/xpath-functions';fn:doc('some.xml')" However I cannot use fn:unparsed-text() from a command line, when a namespace declaration with a protocol is present. I have tried to do java org.basex.BaseX "declare namespace fn='http://www.w3.org/2005/xpath-functions';fn:unparsed-text('some.xml')" but I keep getting this: Stopped at ., 1/79: [FOUT1170] Static Base URI is undefined. This is strange, because the command works fine without the namespace declaration: java org.basex.BaseX "unparsed-text('some.xml')" What can I do to use both namespace declarations and fn:unparsed-text from within a single command line? Best regards Gunther

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Access-Control-Allow-Origin
by lambert strether 18 Jan '17

18 Jan '17

Hi: This is probably an extremely newbie-ish question. I'm developing on localhost using MAMP/PHP at port 8888, and basex at port 8984. So I am running into "Cross-Origin Resource Sharing" issues, apparently, when I have the PHP server issue an XMLHttpRequest to the Basex server. I would have thought that this line in my REST GET function %rest:header-param("Access-Control-Allow-Origin", "http://localhost:8888") in my *.xqm file would have solved the problem. Instead, I'm getting this error: 400 (Stopped at /Users/shunting/basex/webapp/restxq.xqm, 395/14: [bxerr:BASX0003] Invalid path template: "http://localhost:8888".) I'm stymied because I don't see how a URL could match a path template in the first place. Is the "Access-Control-Allow-Origin" not a supported parameter? All I want to do is get my two servers on my machine to talk to each other. If this isn't the right way, is there another one? Thank you! * * * Every communication from this account is off the record, unless explicitly put on the record.

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Gravierende Performance-Einbüße bei Persistierung von mehr als 5000, 160 KB große XML Datenstrukturen.
by Bularca, Lucian 18 Jan '17

18 Jan '17

Guten Tag, im Rahmen einer Performance-Evaluierung der Persistierung von XML Datenstrukturen in einer BaseX Datenbank, haben wir stetig absinkende Persistierungs-Raten umgekehrt proportional zu der Datenbank-Größe festgestellt. Dieses Verhalten ist erklährbar und wäre auch einnehmbar, wenn nicht die Dauer der Persistierung einer ~ 160 KB großen XML Datenstruktur, von Anfang ~ 10 ms auf ~ 2500 ms kommne würde, nach ~ 50.000 Persistierungs-Vorgänge. Dabei versuchen wir 100.000 unterschiedliche, ungefähr 160 KB große XML Datenstrukturen mittels der Java API in eine BaseX Datenbank zu speichern um dabei die Gesammt-Dauer bzw. die Dauer der einzelnen Persistierungs-Vorgänge zu messen. Die BaseX Datenbank wurde im HTTP Modus (basexhttp) mit -Xmx 4048m gestartert. Die oben genannte Messwerte blieben gleich, unabhängig davon, ob alle XM Datenstrukturen in eine einzige Session gespeichert wurden, oder wenn alle 500 Persistierungs-Vorgänge der Socket (DB-Anbindung) geschlossen und erneut geöffnet wurde. Eine Indizierung der Datenbank (mittels der GUI "Optimize All", bzw. "Create Text Index") zwischendurch konnte die Persistierungs-Raten nicht beeinflussen bzw. optimieren. Ein Beispiel der Test-Klassen (nur exemplarisch, nicht kompilierbar !) die wir dazu benutzt haben, sind im Anhang BaseXClient.java.zip zu dieser E-Mail zu finden. Sind generell, Persistierungs-Raten von mehr als 160 KB / 2500 ms bei mehr als 30.000 vorhandene Einträge in der BaseX zu erwarten, oder können wir diese Persistierungs-Zeiten drastisch optimieren (und wenn ja, wie)? Mit freundlichen Grüßen, Lucian Bularca

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How to optimally and reliably go about sequentially applying updates with long running transactions?
by Mustard Seed 14 Jan '17

14 Jan '17

I'm new to BaseX and XQuery, so I apologize if there's some glaring thing I've missed. What I have are three updating functions that I'm wanting to have executed sequentially, successfully, to BaseX. When I simply place them in my RestXQ function, delimited by commas, they all execute, but since at times certain ones take longer than others, and since their results can overwrite/negate the results of each other, I can't manage to get them to consistently execute in the same order. It seems to me that since it seemingly is running in parallel that whatever happens to end last determines what my final state is. I imagine there's got to be some blatantly obvious way to do this, but I'm just not finding it, I went through the BaseX manual a second time and have searched every possible combination of things I can think of to try and figure out a way around this. One function does a mass delete of all dbs with a given prefix, another repopulates from a sql query, and a third updates the repopulated dbs based on yet another sql query. That's the order I want it to execute in, I'm just about at my wits end trying to figure out how to do this. I was even getting into trying to pull off a hackish attempt at making jobs which I'd schedule based on a rough guess of the longest expected execution times for the functions. But even that wasn't working. Any help will be greatly appreciated as insuring the order of execution is rather vital for the overall project I'm trying to do, so I need to not only find a solution for the present use case, but I need to understand how to insure such for any future composite functions. Thanks, --Nicolai

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format-number rounding
by George Sofianos 14 Jan '17

14 Jan '17

Hi there, I was wondering if there is a similar function to format-number, but without rounding, so I don't have to create a custom one that involves string manipulation. For example I have two values: let $x := <value>15.224134</value> let $y := <value>15.2249348734</value> The following command will create different output for the two values (result for $x will be 15.224, result for $y will be 15.225) format-number(xs:decimal($x), "0.000")) Thanks, George

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Speeding up fn:id()
by Sebastian Zimmer 12 Jan '17

12 Jan '17

Hi all, I am surprised that fn:id() does take quite a long time in contrast to (almost) equivalent XPaths. An example: > XQUERY collection('zk/')//id('zkI_108-5_R') <div xmlns="http://www.tei-c.org/ns/1.0" xml:id="zkI_108-5_R"> ... </div> Query executed in 5956.43 ms. > XQUERY collection('zk/')//*[@xml:id='zkI_108-5_R'] <div xmlns="http://www.tei-c.org/ns/1.0" xml:id="zkI_108-5_R"> ... </div> Query executed in 9.43 ms. Couldn't the first XQuery be optimized into the second? If not, maybe an xml:id index would be a good feature. eXist-db does have one, particularly dedicated to speed up fn:id() [1]. Best regards, Sebastian Zimmer [1] http://exist-db.org/exist/apps/doc/indexing.xml -- <---------- Sebastian Zimmer sebastian.zimmer(a)uni-koeln.de Cologne Center for eHumanities (CCeH) - Universität zu Köln - http://www.cceh.uni-koeln.de ------------------------------------>

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