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

Creating db in restxq interface
by Henning Phan 24 May '16

24 May '16

Hi, My question is how do you create a new database in restxq?When trying to create a db I get the error msg:HTTP Error 400[XUST0001] element constructor: no updating expression allowed.Some digging around and I learned that I might need the "updating" annotation though even after the change it gives the same error.My file looks like this now:=========== File start ================ declare %rest:path("/start") %updating %output:method("xhtml") %output:omit-xml-declaration("no") %output:doctype-public("-//W3C//DTD XHTML 1.0 Transitional//EN") %output:doctype-system("http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd") function page:hello() as element(Q{http://www.w3.org/1999/xhtml}html) { <html xmlns="http://www.w3.org/1999/xhtml"> <title>Good day Sir!</title> <link rel="stylesheet" href="static/w3.css"/> <time>The current time is: { current-time() }</time> <body class="w3-container"> <ul class="w3-navbar w3-green"> <li><a href="#">Home</a></li> <li><a href="#">Link 1</a></li> <li><a href="#">Link 2</a></li> <li><a href="#">Link 3</a></li> </ul> <ul>{ for $result in db:open('factbook')//continent/@name return <li>{ data($result) }</li> }</ul> <li> { db:create("test") } </li> </body> </html> =========== File End ================

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Querying Basex from a web interface
by Bram Vanroy | KU Leuven 22 May '16

22 May '16

Hello all I have been reading through many emails on this list and I've learnt a lot about how Basex works and how others use it. A month or so back I have sent an email myself to this list concerning caching. Even though I have some more questions about that, I will leave that for another time. Today I am concerned about retrieving chunked input from Basex. (Question also found on StackOverflow, with a nice bounty! :) http://stackoverflow.com/questions/36675388/efficient-and-user-friendly-way- to-present-slow-loading-results) Case at hand: we use Basex to query a 50 million tokens corpus. We also make this available to other users through a website. The thing is that this is slow. For our own projects that's no problem, we dive straight into the back-end and run a search command from terminal and let the query run for all the time it needs. However, for users it is paramount that they get a quick response. At the moment it is taking too long. I don't blame BaseX. We love BaseX and are astounded by its efficiency and optimisations! However, we want to deliver the best user-experience to our users. We call a new session from PHP, wait to receive the results, do some post-processing and then load the result page. As said, this takes too much time. We've been looking into some solutions. The best one that I think should be possible, is returning chunks of the results. Do you know those websites that allow you to see results but only, like, 20 per page? I think something similar is appropriate. When a user has searched for a pattern, we only show the 20 or so first results just so they can get an idea of the results they'd find. Then, when they click a button, we should query for the twenty next results which are then appended to the list (JavaScript solution I guess), and so on. Until all results have been found. Additionally, I will also provide a button from which users can download all results in a text file. This is allowed to take a longer time. The main thing is that users should get early feedback and results on their query. Now the question is if something like this is possible in an efficient manner in BaseX. Can you form a query that only finds the 20 first results, and then the following 20 and so on - and is this faster than searching everything at once? In other words, when I am searching for the results 120-140 (after having pushed the button a couple of times), is BaseX smart enough to skip the search space it has already done to find the 120 previous hits? If so, that would be great. Could you help me on my way, with some PHP/XQuery code that is suitable? I also highly encourage you to participate on StackOverflow. As I said, I am offering a 200 bounty - for the people who are interested in Internet fame. :) Thank you for your time Kind regards Bram Vanroy http://bramvanroy.be

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dba lags on replace resource
by Marco Lettere 22 May '16

22 May '16

Hi all, I have a single resource in a db. I perform several replace operations on that resource. The dba interface shows an increasing number of resources available in the db according to the number of replace operations performed. To get the count of resources back to 1 I need to optimize the database. When opening the database the visible content is however correct (showing the only one resource). Feels like dba is somehow lagging the information displayed with respect to the db content .... Regards, Marco.

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RESTXQ and xsd validation strangeness
by Marco Lettere 22 May '16

22 May '16

Dear all, this question triggers a dejavu in my head and I'm pretty sure this has been discussed some time ago so I'm not sure why it strikes back at us ... With the latest snapshot (but with 8.4.4 it's the same) downloaded just few minutes ago I start the basehttp server. Then I add the foolowing RestXQ to the restxq.xqm file: declare %rest:path("/testxsd") %rest:POST("{$body}") %rest:consumes("application/xml") function page:testxsd($body){ validate:xsd-info($body, "xsd.xsd") }; I store the following dummy xsd as xsd.xsd in the webapp folder: <?xml version="1.0"?> <xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema"> <xs:element name="a"/> </xs:schema> I invoke the restxq with: curl -vd "<a/>" http://localhost:5000/testxsd -H "Content-type:application/xml" Getting back the following error: Error 400 Stopped at /tmp/basex/webapp/restxq.xqm, 12/20: [bxerr:BXVA0002] Validation could not be started: Resource "/tmp/basex/POST.xml (No such file or directory)" not found.</title> This happens no matter what xml and what xsd is used. If I change $body with <a/> in the call to validate:xsd-info everything works smoothly ... Any ideas? Thanks, Marco.

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Re: [basex-talk] Faceted search
by Finney, Tim 22 May '16

22 May '16

Hi All, I would love to see faceted search capability. Sorry, but I can't offer sponsorship. Two things I would love to see in BaseX are faceted search capability (fast, index-based) and role-based security. Best, Tim Finney ------ Hi Greg, currently there is no out-of-the-box functionality, yet there is an EXPath Specification that handles facets: http://expath.org/spec/facet We have not yet implemented it in BaseX, but we might eventually if there is enough interest and maybe even a sponsor :-) Would that module cover your needs? Best Michael

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connection question
by Wang, Genneva 22 May '16

22 May '16

Hi basex gurus, One other question. We internally have connection pools of 20 connecting to basex. While trying to do performance stress test using Jmeter, we found out that if we submit more than the configured connection pool, say submit 30 connections, we noticed that the connection will not be recovered and the connection pool size will be in a un-recovereable stage (to pool size 0 eventually). I was just wondering does basex does any queueing on the receiving the incoming transactions, or is this something that the application needs to handle? Any tips would be greatly appreciated! Thank you very much. Regards, —Genneva

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Basex: basexhttp Failing to Start with "Server is running or permission was denied"
by Sovello Hildebrand Mgani 22 May '16

22 May '16

Hi! I have downloaded BaseX 8.4.4 and running it on Ubuntu 14.04[.4] I have added basex/bin to $PATH so I can be able to run basex, basexhttp ecc. I can successfully run basex and basexserver. RUnning the HTTP server fails with this message *$ basexhttp* [main] INFO org.eclipse.jetty.server.Server - jetty-8.1.18.v20150929 [main] INFO org.eclipse.jetty.webapp.StandardDescriptorProcessor - NO JSP Support for /, did not find org.apache.jasper.servlet.JspServlet [main] INFO / - Aliases are enabled! Security constraints may be bypassed!!! Server was started (port: 1984). [main] INFO org.eclipse.jetty.server.AbstractConnector - Started SelectChannelConnector@0.0.0.0:8984 HTTP Server was started (port: 8984). Server is running or permission was denied. Server was stopped (port: 1984). and the output when I run *$ basexhttp -d* DEBUG: true BaseX 8.4.4 [HTTP Server] [main] INFO org.eclipse.jetty.server.Server - jetty-8.1.18.v20150929 [main] INFO org.eclipse.jetty.webapp.StandardDescriptorProcessor - NO JSP Support for /, did not find org.apache.jasper.servlet.JspServlet [main] INFO / - Aliases are enabled! Security constraints may be bypassed!!! WEBPATH: /opt/oim/basex/webapp DEBUG: true Server was started (port: 1984). [main] INFO org.eclipse.jetty.server.AbstractConnector - Started SelectChannelConnector@0.0.0.0:8984 HTTP Server was started (port: 8984). java.net.BindException: *Address already in use* at java.net.PlainSocketImpl.socketBind(Native Method) at java.net.AbstractPlainSocketImpl.bind(AbstractPlainSocketImpl.java:387) at java.net.ServerSocket.bind(ServerSocket.java:375) at java.net.ServerSocket.bind(ServerSocket.java:329) at org.basex.BaseXHTTP$StopServer.<init>(BaseXHTTP.java:430) at org.basex.BaseXHTTP.<init>(BaseXHTTP.java:147) at org.basex.BaseXHTTP.main(BaseXHTTP.java:52) Server is running or permission was denied. Server was stopped (port: 1984). Which shows address is already in use. I only have apache2 and have run apache2 and tomcat earlier on the same laptop without issues, and I don't have any service that is listening on that port 8984. (I have tried running BaseX from version 8.0 and get the same errors). Am not sure what is not OK. Can you give me pointers to resolve this? Cheers -- :: Sovello Hildebrand Mgani :: --If you teach man to fish, you'll feed him a lifetime--

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file:write - check, if path is existing
by Günter Dunz-Wolff 20 May '16

20 May '16

Hi all, for the command file:write($path, distinct-values($list)) I have to check, if $path is existing (for example let $path := ´users/xxx/xxx/etc’. How is it done in XQuery? Thanks for any help. Cheers, Günter

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Xquery recursion and db:add() - stack overflow
by Lars Johnsen 18 May '16

18 May '16

The following code generates the error "Stack Overflow: try tail recursion?" The code reads in bibliographic data using OAI-PMH and updates a database for each chunk of data. With OAI-PMH, only part of the data is available for each request, so the server returns a resumption token if there are more data available. The xquery function making the queries is implemented recursively preceded by a database update request (see the last two lines) for each call. Is it db:add() that causes the stack overflow? The recursion cannot be placed further towards the end! declare %updating function local:getResumption($token) { if (empty($token)) then () else let $http-request := http:send-request($http-option, $URL || $token) let $result := if ($http-request instance of node()) then $http-request else <http-err>{$http-request}</http-err> let $resume := $result//oai:resumptionToken/text() return ( db:add($database,element chunk {$result//oai:metadata}, $path) , local:getResumption($resume) ) }; Best, Lars

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Faceted search
by Murray, Gregory 18 May '16

18 May '16

Hello, Does BaseX have built-in support for faceted search? I see that there's an easy way to get the facets for the entire database using index:facets(), but is there way to get search results that includes a similar list of facets, based only on those results? Thanks, Greg

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