BaseX-Talk March 2017

basex-talk@mailman.uni-konstanz.de

32 participants
43 discussions

Gzipped compression
by meumapple 13 Mar '17

13 Mar '17

Hi, I am trying to enable gzipped compression in RESTXQ. I have been modifying web.xml without success. Where should the filter element [1] be put? Thanks. Joseph [1] (http://www.srccodes.com/m/p/article/12/configure-gzip-filter-on-jetty-8-for…)

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Basexhttp on ubuntu
by Trevor Sewell 12 Mar '17

12 Mar '17

I’ve Installed base via apt on ubuntu 16.10 I can run basex, basexserver but not basexhttp, the command is not found please advise

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Re: [basex-talk] RETRIEVE
by Christian Grün 11 Mar '17

11 Mar '17

For returning specific XML documents of a database, you need to use the XQUERY command: XQUERY db:open('greek', 'PROSE~aristotle~Rhetoric1') All documents of the currently opened database can simply be addressed and returned via the context item (.): XQUERY . Hope this helps, Christian Am 11.03.2017 10:08 nachm. schrieb "mark bordelon" <markcbordelon(a)yahoo.com >: > In actuality, as you have surmised, no. > I wish to get the xml text of document. > So, for what I am attempting below ... > > *> list * > *Name Resources Size Input Path * > *------------------------------ ----------* > *greek 2 2942906 * > *latin 184 9942769 * > *semantic 785 257685 * > > *3 database(s).* > *> list greek* > *Input Path Type Content-Type Size * > *------------------------------ ------------------------------* > *PROSE~aristotle~Rhetoric1 xml application/xml 99387 * > *PROSE~CONVERSATION~ GreekPrimer xml application/xml 20260 * > > *> open greek* > *Database 'greek' was opened in 2.9 ms.* > *> retrieve PROSE~aristotle~Rhetoric1* > > .. my intention is to have the xml content: *<text><sent><clause> ...... > </text>* > > ------------------------------ > *From:* Christian Grün <christian.gruen(a)gmail.com> > *To:* mark bordelon <markcbordelon(a)yahoo.com> > *Cc:* BaseX <basex-talk(a)mailman.uni-konstanz.de> > *Sent:* Saturday, March 11, 2017 12:25 PM > *Subject:* Re: [basex-talk] RETRIEVE > > What are your intentions? Are you really interested in a raw > representation of your input? > > Am 11.03.2017 21:24 schrieb "mark bordelon" <markcbordelon(a)yahoo.com>: > > Christian, thank you. > Can you give me an example of the syntax (e.g. command + param) of the > RETRIEVE command in my case? > > > ------------------------------ > *From:* Christian Grün <christian.gruen(a)gmail.com> > *To:* mark bordelon <markcbordelon(a)yahoo.com> > *Cc:* BaseX <basex-talk(a)mailman.uni- konstanz.de > <basex-talk(a)mailman.uni-konstanz.de>> > *Sent:* Saturday, March 11, 2017 12:21 PM > *Subject:* Re: [basex-talk] RETRIEVE > > Hi Mark, > > Each resource is stored as either an XML document or a binary file (raw > data) [1]. You can only retrieve resources as raw data of they have been > stored as binaries. > > Hope this helps, > Christian > > [1] http://docs.basex.org/ wiki/Binary_Data > <http://docs.basex.org/wiki/Binary_Data> > > > > > Am 11.03.2017 21:16 schrieb "mark bordelon" <markcbordelon(a)yahoo.com>: > > I am trying to retreieve the raw xml from a document and think I should > use the RETRIEVE command, right? What is the ID that I pass as the argument? > Here is what I have tried with the error: > > > *list* > Name Resources Size Input Path > ------------------------------ ---------- > greek 2 2942906 > latin 184 9942769 > semantic 785 257685 > > 3 database(s). > > *list greek* > Input Path Type Content-Type Size > ------------------------------ ------------------------------ > PROSE~aristotle~Rhetoric1 xml application/xml 99387 > PROSE~CONVERSATION~ GreekPrimer xml application/xml 20260 > > > *open greek* > Database 'greek' was opened in 2.9 ms. > > *retrieve PROSE~aristotle~Rhetoric1* > *Resource "PROSE~aristotle~Rhetoric1" not found.* > > > > > > >

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Re: [basex-talk] RETRIEVE
by Christian Grün 11 Mar '17

11 Mar '17

Hi Mark, Each resource is stored as either an XML document or a binary file (raw data) [1]. You can only retrieve resources as raw data of they have been stored as binaries. Hope this helps, Christian [1] http://docs.basex.org/wiki/Binary_Data Am 11.03.2017 21:16 schrieb "mark bordelon" <markcbordelon(a)yahoo.com>: I am trying to retreieve the raw xml from a document and think I should use the RETRIEVE command, right? What is the ID that I pass as the argument? Here is what I have tried with the error: > *list* Name Resources Size Input Path ---------------------------------------- greek 2 2942906 latin 184 9942769 semantic 785 257685 3 database(s). > *list greek* Input Path Type Content-Type Size ------------------------------------------------------------ PROSE~aristotle~Rhetoric1 xml application/xml 99387 PROSE~CONVERSATION~GreekPrimer xml application/xml 20260 > *open greek* Database 'greek' was opened in 2.9 ms. > *retrieve PROSE~aristotle~Rhetoric1* *Resource "PROSE~aristotle~Rhetoric1" not found.*

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Simple query
by Aaron Weber 11 Mar '17

11 Mar '17

Newbie alert. I'm trying to get my feet wet with BaseX, and in doing so, am trying to understand XQuery and how to apply it to a database full of documents (not just a single document that is typically queried). I am using Java and can post my code, but with a LocalSession, and a query, the following produces 0 results. For $doc in collection() return $doc I realize there's no "where", and in the sql world that would match all. Maybe not in XQuery? Obviously just a test query, but I need to start somewhere. :-) Thanks for any help! -- AJ

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Tail Recursion Error on startup
by buddyonweb-software＠yahoo.com 11 Mar '17

11 Mar '17

When we start up BaseX (whether the server or the GUI) and run a particular a query against a particular .xqm file, we always get a tail recursion error. Error:[bxerr:BASX0005] Stack Overflow: Try tail recursion? If we attempt to execute it again (sometimes twice, but have done so repeatedly up to 5 times), the error goes away and all is fine. Is there anything you can suggest or anything we can provide you to see how to eliminate this. This is particularly problematic on our server when we reboot our production application.Anything you can suggest or anyway we can help is much appreciated. Buddy

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Angular(2) ToH with Basex backend
by Rob Stapper 11 Mar '17

11 Mar '17

Hi, So finally I got the Tour of Heroes from the Angular(2) tutorial [1] working with BaseX as database backend. Everything works pretty well except for one thing: When adding a new record, Angular expects the backend (BaseX) to create an unique ID for the record and send it, together with the original, back to the angular-frontend [2]. In BaseX however, it is not possible to retrieve updated data from within the same transaction as the update of the database took place. The work around is to fetch the updated record outside the updating-transaction by means of a web:redirect to the link that retrieves a record [3]. This work around has two major disadvantages: 1. one can never be a 100% sure that the fetched data is exactly the data as it was stored in the base because updating and fetching are two separate transactions. 2. this only works if the records have a unique set of key fields. This doesn't always have to be the case. I've reported this situation a while ago and I wouldn't come back on it if the Angular-way of working didn't come up with the same situation. In my opinion BaseX would even be better equipped as database backend as it is if it was possible to fetch the updated date in the database from within the same transaction as the update took place. Is this something that could be considered for a future release? Cheers, Rob Stapper PS. I got this far thanks to the suggestions on CORS. [1] https://angular.io/docs/ts/latest/tutorial [2] https://angular.io/docs/ts/latest/tutorial/toh-pt6.html chapter: "Add a hero". [3] declare %rest:path("/product/save") %rest:POST("{ $parameterSet}") %updating function _:product.save ( $parameterSet as array(*) ) { ( db:output( web:redirect( "/product/find" , map{ "code" : $parameterSet(2) } ) ) , dbx:save( $_:dataBase , $_:objectType , trace( $parameterSet(1), "objectID:" ) , product:new( $parameterSet(2) , $parameterSet(3) , $parameterSet(4) ) ) )

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Flush command and data corruption
by Colin Delacroix 10 Mar '17

10 Mar '17

Hi everyone, (warning this is a long read) I'm using server version 8.6.1 and writing a Java client to move lots of documents from a SQL database to a BaseX database. The basic version works just fine. Tested up to 1M documents. Now I'm trying to do exactly the same but with AUTOFLUSH disabled + manually FLUSH every N documents and it fails after just a few inserts. Pseudo code: (set up client session, create and open new database) session.execute(new Set(MainOptions.AUTOFLUSH, false)); int i = 0; while(doc = nextDocs()) { session.add(doc.getKey(), doc.getInputStream()); if(i++ % 10 == 0) { /* value reduced to 10 for testing purposes */ session.execute(new Flush()); } } (tear down session) Remember tha After the first FLUSH has been issued, the ADD directive starts randomly throwing a org.basex.core.BaseXException (when using the BaseXClient implementation it was its inner ok() method that started returning false). I tracked the root cause in the server: the SAXParser complaining about the documents not being well-formed (the exact same documents are all imported fine with AUTOFLUSH on). In the server standard logs I can see why: parts of those documents are suddenly missing (usually the beginning + command part) at parse time! That is the symptom, now for the cause I'm also observing that the ADD and FLUSH directive in the logs are out of order, exactly like what would happen in the FLUSH commands were not properly queued. I was expecting something like : ADD ADD ADD (N times) FLUSH ADD ADD ADD (N times) FLUSH etc. Instead I'm observing ADD FLUSH ADD FLUSH ADD FLUSH (etc) then ADD ADD ADD (lots of them) ERROR So for now I'm keeping autoflush on :) but is there anything obvious I could try there? (server runs on linux openjdk 1.8.0_91, client runs in Tomcat on Windows Oracle JDK 1.8.0_121) Thanks, Colin

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[XPTY0004] Item expected, sequence found
by Bram Vanroy 08 Mar '17

08 Mar '17

Hi BaseX peeps I'm running BaseX 8.6.1 on Windows, and I'm running into an issue I can't explain. I am using BaseX to run some benchmarks. As a benchmark I am running different XPath structures to match on the same database. In other words, in a file of a hundred lines each line is an XPath structure, and with Perl I query each line and measure the time it takes. Simple enough, right? The strange thing is that my script runs fine but it crashes on line 17, which is this XPath code: //node[@cat="pp" and node[@rel="hd" and @pt="vz" and number(@begin) < number(../node[@rel="obj1" and @cat="np"]/node[@rel="mod" and @cat="pp"]/node[@rel="hd" and @pt="vz"]/@begin)] and node[@rel="obj1" and @cat="np" and node[@rel="mod" and @cat="pp" and node[@rel="hd" and @pt="vz" and number(@begin) < number(../node[@rel="obj1" and @cat="np"]/node[@rel="mod" and @cat="pp"]/node[@rel="hd" and @pt="vz"]/@begin)] and node[@rel="obj1" and @cat="np" and node[@rel="mod" and @cat="pp" and node[@rel="hd" and @pt="vz"]]]]]] Admittedly, it's quite a long string, but I don't see anything wrong with it and I don't think the error lies in the XPath. The full trace is like follows: [XPTY0004] Item expected, sequence found: (attribute begin {"6"}, ...). at C:\xampp\htdocs\grinding\BaseXClient.pm line 213. at C:\xampp\htdocs\grinding\BaseXClient.pm line 213. Query::exc("\x{5}", 133) called at C:\xampp\htdocs\grinding\BaseXClient.pm line 177 Query::execute(Query=HASH(0x3adac40)) called at SonarBenchNew.pl line 249 main::query_sonar("for \$node in db:open(\"WRPEE0000000treebank\")/treebank//node[\@"...) called at SonarBenchNew.pl line 176 main::loop_databases(ARRAY(0x31a2ae0), "//node[\@cat=\"pp\" and node[\@rel=\"hd\" and \@pt=\"vz\" and number(\@"...) called at SonarBenchNew.pl line 140 main::regular_sonar("//node[\@cat=\"pp\" and node[\@rel=\"hd\" and \@pt=\"vz\" and number(\@"...) called at SonarBenchNew.pl line 110 I have found that the XPTY0004 error is often caused by an order-by clause in XQuery but I don't have that. The full XQuery for the XPath is as follows: for $node in db:open("WRPEE0000000treebank")/treebank//node[@cat="pp" and node[@rel="hd" and @pt="vz" and number(@begin) < number(../node[@rel="obj1" and @cat="np"]/node[@rel="mod" and @cat="pp"]/node[@rel="hd" and @pt="vz"]/@begin)] and node[@rel="obj1" and @cat="np" and node[@rel="mod" and @cat="pp" and node[@rel="hd" and @pt="vz" and number(@begin) < number(../node[@rel="obj1" and @cat="np"]/node[@rel="mod" and @cat="pp"]/node[@rel="hd" and @pt="vz"]/@begin)] and node[@rel="obj1" and @cat="np" and node[@rel="mod" and @cat="pp" and node[@rel="hd" and @pt="vz"]]]]]]let $sentid := ($node/ancestor::alpino_ds/@id)let $sentence := ($node/ancestor::alpino_ds/sentence)let $tb := \'WRPEE0000000treebank\' return <match>{data($sentid)}||{data($sentence)}||{data($tb)}</match> I don't know if you guys can give me directions solely based on this. But if you could point me to a likely cause, e.g. input OR database contents, that would be great. Thanks in advance! Bram Vanroy https://bramvanroy.be

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Re: [basex-talk] starting and closing HTTP server giving errors
by kalibuk＠centrum.cz 08 Mar '17

08 Mar '17

Hi Marco, thanks for reply I tried your latest release (8.6.2.x) and it seems helped to get HTTP server stopped ok. Otherwise starting the server is still giving me the error. Automation is out of way as it may be reproduced manually in command line see: c:\>basexhttp.bat -S Connection failed (port: 8984). c:\>basexhttpstop.bat HTTP Server was stopped (port: 8984). c:\> Any idea why it hands back connection failed message while I can ping it like this while running? C:\windows\system32>netstat -anb | find "8984" TCP 0.0.0.0:8984 0.0.0.0:0 LISTENING TCP [::]:8984 [::]:0 LISTENING Thanks, Jan -------------------------------------------------------------------------------------------------------------------------------------------- Hallo, I'm trying to get strating and stopping of BaseX HTTP server automated. ? Whats wrong with starting: Once trying to run in command line "basexhttp.bat -S" I get "Connection failed (port: 8984)." But server is running (!?) and I can create socket to comunicate with. ? Whats wrong with stopping: Once trying to run in command line "basexhttpstop.bat" I get it hanged and need to terminate job or on another attempt I get back "Connection failed (port: 8985)." And I cannot communicate with server so it seems that it really got stopped. ? It's tricky to automate that if I get errors on every attempt to start/stop it. Could you advice? ? Third error what I ocasionally can get back after trying to run server is: "Error occurred during initialization of VM Could not reserve enough space for 1433600KB object heap" ? Behaviour is same for 8.6.0 and 8.6.1. I have just updated Java RT to latest. ? Regards,? Jan, Brno ? ? ?

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BaseX-Talk March 2017