BaseX-Talk November 2011

basex-talk@mailman.uni-konstanz.de

44 participants
65 discussions

BaseX 7.0.1: Release early, release often..
by Christian Grün 06 Nov '11

06 Nov '11

Hi all, we are glad to announce BaseX 7.0.1, which is basically the result of your initial feedback on 7.0. Those are the most important changes: DISTRIBUTIONS: - Windows installer was updated to support latest features - ZIP file was updated (initial config & directories added) - Short directory names are chosen if config file resides in app.dir. - Start scripts have been improved XQUERY: - much faster execution of count() when applied to opened databases SERVER (http://docs.basex.org/wiki/Startup_Options#BaseX_HTTP_Server): - Flag -c connects to an existing database server - Flag -s specifies a port for stopping the HTTP server (Jetty) - Flag -S starts the HTTP server as a service - running write operations will be completed before server is stopped API: - Ruby, Python, PHP, Java: clients updated Please check out the well-known links: - Homepage: http://basex.org/ - Documentation: http://docs.basex.org/ - Snapshots: http://files.basex.org/releases/latest/ - Sources: https://github.com/BaseXdb Enjoy the update! Christian BaseX Team

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Simple Xquery '(/org)[1 to 5]' was failed in GUI
by 方立厅 05 Nov '11

05 Nov '11

Hi Michael, Thanks for your replying. So this BaseX does not compatible to XQuery 1.0 by this feature? "(/org)[$start to $end]" query excuted well in marklogic and bdbxml. And I need a solution to make my existing xquery modules could be exuted in BaseX without modifying the codes. Any suggestion? Thank you, Edward >> Dear Edward, >> >> the correct syntax is: >> (2 to 100)[position() = 5 to 20] > (sequence)[5] is only a shorthand for (sequence*)[position() eq 5] wher 'eq' compares two _single_ items for equality. > > With [positon() = 5 to 20] we perform a general comparison, such that the predicate evaluates to true if comparison of any of the items inside both sequences > evaluates to true. > Thus position() = (5,6,7,?,20) evaluates to true if position() is between 5 and 20, while > position() eq (5 to 20) throws an error, as eq is not allowed to compare single items with sequences. > > Hope this helped clear things up a little, s/o please correct me if my explanation was faulty :-) > > Thanks > Michael > Am 05.11.2011 um 03:54 schrieb ???: > >> Hi, >> I'm using BaseX first time. and using 7.0.1. >> about 5000 org.xml was loaded into the db in my test enviroment. >> >> But I got an error msg instead of the result i want when I was excuting an simple xquery '(/org)[1 to 5]' in GUI: >> Query: (/org)[1 to 5] >> Error: [FORG0006] (1 to 5) not allowed as condition type. >> >> The xquery '(/org)[position()> 2 and position()< 5]' excuted very well. >> >> Thanks, >> Edward >> >> _______________________________________________ >> BaseX-Talk mailing list >> BaseX-Talk(a)mailman.uni-konstanz.de >> https://mailman.uni-konstanz.de/mailman/listinfo/basex-talk

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Simple Xquery '(/org)[1 to 5]' was failed in GUI
by 方立厅 05 Nov '11

05 Nov '11

Hi, I'm using BaseX first time. and using 7.0.1. about 5000 org.xml was loaded into the db in my test enviroment. But I got an error msg instead of the result i want when I was excuting an simple xquery '(/org)[1 to 5]' in GUI: Query: (/org)[1 to 5] Error: [FORG0006] (1 to 5) not allowed as condition type. The xquery '(/org)[position() > 2 and position() < 5]' excuted very well. Thanks, Edward

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Re: [basex-talk] Importing a document using xquery statements?
by Lukas Kircher 04 Nov '11

04 Nov '11

So far there is no XQuery function that allows you to create or delete a database. I remember this being a conscious design decision, as creating/deleting a database requires CREATE permissions, but I might be wrong... Maybe one of my team mates can help me out here? Cheers, Lukas On Fri, Nov 4, 2011 at 10:22 AM, Erdal Karaca < erdal.karaca.de(a)googlemail.com> wrote: > Thanks for the quick reply! > Unfortunately, this function needs an existing database. I could not > find a function like db:create or the like... How would i create the > database, first? > > > 2011/11/4, Lukas Kircher <lukaskircher1(a)googlemail.com>: > > Hi Erdal, > > > > you could have a look at our BaseX-specific database functions - > > db:add() [1] might be what you are looking for. > > > > Hope I could help, regards, > > Lukas > > > > > > [1] http://docs.basex.org/wiki/Database_Functions#db:add > > > > > > > > On Fri, Nov 4, 2011 at 9:54 AM, Erdal Karaca < > erdal.karaca.de(a)googlemail.com > >> wrote: > > > >> I have set up eclipse XQDT to use basex as interpreter... Now, I need > >> to import a document into a database. Is that possible without using > >> the server commands in a command line? For example some basex specific > >> functions? > >> _______________________________________________ > >> BaseX-Talk mailing list > >> BaseX-Talk(a)mailman.uni-konstanz.de > >> https://mailman.uni-konstanz.de/mailman/listinfo/basex-talk > >> > > > > > -- > 1 + 1 = 10 >

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Importing a document using xquery statements?
by Erdal Karaca 04 Nov '11

04 Nov '11

I have set up eclipse XQDT to use basex as interpreter... Now, I need to import a document into a database. Is that possible without using the server commands in a command line? For example some basex specific functions?

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Windows fast, linux very slow
by Sven Rega 03 Nov '11

03 Nov '11

Hy, i'm using the basexserver 6.7.1 on a windows (i7; 8GB; 2,8GHz) and on different linux machines (i7; 16GB, 3,4GHz). the same xml file (~2,5GByte) and one simple query has i big difference in speed between both machines and i don't know, where the bottleneck is coming from. on the windows machine i get througput of ~600 to 1000 xml entities per second. On the linux machine i only get max. 110 xml entities per second. I use the same jvm setting on both machines: -server -Xmx3g I also use the index (text, path, attribtue) on both machines. The query: "declare function local:ProductValues() { for $n in //Product[(@ID='A' or @ID='D' or @ID='G')]/Values return <pv><utid>{data($n/../@ID)}</utid><id>{data($n/../@SecondID)}</id>{$n}</pv> }; local:ProductValues()" I read from the basex server over lan with 1GBit. Does anybody have a idea, what could be the reason for such speed difference between windows and linux? king regards Sven

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Re: [basex-talk] Basex plot view
by Constantine Hondros 03 Nov '11

03 Nov '11

[ahem] ... just to clarify, the scatter-plot renders against a blank background, and not a map, like in the visualisation documentation. Is there any way to specify BaseX to plot the points against a map? ________________________________ From: Constantine Hondros Sent: Thursday, November 03, 2011 4:45 PM To: basex-talk(a)mailman.uni-konstanz.de Subject: Basex plot view Hi, I've got some geographical data loaded in Basex 7.1 and I was hoping to configure the plot view easily to render latitude/longitude values against a map, like the documentation suggests: http://docs.basex.org/wiki/GUI_Tutorial#Visualizations and http://basex.org/products/gui/ I can't seem to figure this one out though - any hints? Thanks ;-) Constantine Hondros | Senior Data Engineer | TomTom Places | constantine.hondros(a)tomtom.com<mailto:constantine.hondros@tomtom.com> | +31 (0) 88 245 6239 office | +31 (0) 6 402 14838 mobile | places.tomtom.com<http://places.tomtom.com/>

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Basex plot view
by Constantine Hondros 03 Nov '11

03 Nov '11

Hi, I've got some geographical data loaded in Basex 7.1 and I was hoping to configure the plot view easily to render latitude/longitude values against a map, like the documentation suggests: http://docs.basex.org/wiki/GUI_Tutorial#Visualizations and http://basex.org/products/gui/ I can't seem to figure this one out though - any hints? Thanks ;-) Constantine Hondros | Senior Data Engineer | TomTom Places | constantine.hondros(a)tomtom.com<mailto:constantine.hondros@tomtom.com> | +31 (0) 88 245 6239 office | +31 (0) 6 402 14838 mobile | places.tomtom.com<http://places.tomtom.com/>

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BaseX server deadlock
by Laurent Chevalier 03 Nov '11

03 Nov '11

Hi, A deadlock occurs in the following situation: a first client program opens an iterative query. For each iteration, this program does some processing and sends another reading request to BaseX (using another BaseX session). All works fine until a second client program (or another thread) sends an updating command to BaseX (like optimize for instance). This locks BaseX server. To unlock it, you have to kill the first program. I have read BaseX server code and found the reason for this behavior in the class org.basex.core.Lock: - with the iterative query, there is always at least one reader alive (readers=1). - when the updating query is received, it is put in the queue (index 0) and remains in it as long as there is a reading query running (that is to say, as long as the iterative reading query is running). - then a second reading request is received, it is put in the queue (index 1 as there is already the updating query in the queue). As it is only the second item of the queue, it remains in the queue as long as the first item in the queue (the updating query) has not been processed (BaseX processes the requests in the order of arrival, FIFO queue). But this first item can not be processed because there is the iterative reading query running. All queries are thus locked. Some may say that we should not send another query while we are in the loop of an iterative query but in our context of many sites being developed by several developers, it is possible that a developer codes this and we do not want BaseX to be locked in this case (whatever it is a mistake of the developer or not). I have found a solution to this problem by modifying the org.basex.core.Lock class. You will find my code hereafter. I do not use a queue anymore and i use a static mutex (called queueMutex) to synchronize all pending queries (threads). The "drawback" of this solution is that the queries are not processed anymore in the order of arrival but randomly. What do you think of this solution ? Do you plan to update BaseX locking mechanism ? I'm using BaseX 6.7.1 but I have seen that Lock.java has not been changed in BaseX 6.7.2. Here is my code : package org.basex.core; import java.util.Date; //import java.util.LinkedList; import java.util.Random; import org.basex.util.Util; /** * Management of executing read/write processes. * Supports multiple readers, limited by {@link MainProp#PARALLEL}, * and single writers (readers/writer lock). * * @author BaseX Team 2005-11, BSD License * @author Christian Gruen */ final class Lock { /** Queue for all waiting processes. */ // private final LinkedList<Object> queue = new LinkedList<Object>(); /** Mutex object. */ private final Object mutex = new Object(); /** Database context. */ private final Context ctx; /** Static mutex used to synchronize all pending queries. **/ private final static Object queueMutex = new Object(); /** Number of active readers. */ private int readers; /** Writer flag. */ private boolean writer; /** * Default constructor. * @param c context */ Lock(final Context c) { ctx = c; } /** * Modifications before executing a command. * @param w writing flag */ void lock(final boolean w) { synchronized(mutex) { int code = new Random(new Date().getTime()).nextInt(); // final Object o = new Object(); // queue.add(o); try { while(true) { synchronized(queueMutex) { // if(o == queue.get(0) && !writer) { if(!writer) { if(w) { if(readers == 0) { writer = true; break; } } else if(readers < Math.max(ctx.mprop.num(MainProp.PARALLEL), 1)) { ++readers; break; } } } mutex.wait(); } } catch(final InterruptedException ex) { Util.stack(ex); } // queue.remove(0); } } /** * Modifications after executing a command. * @param w writing flag */ synchronized void unlock(final boolean w) { synchronized(mutex) { if(w) { writer = false; } else { --readers; } mutex.notifyAll(); } } }

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Re: [basex-talk] user setup and server
by Jan Vlčinský (CAD) 03 Nov '11

03 Nov '11

> > It is all about ease of use and security. As handling user accounts is already not the beginner task, I would see reasonable not to grant any rights by default, as Pascal proposed. Jan On 3 November 2011 05:43, Pascal Heus <pascal.heus(a)gmail.com> wrote: > Christian: > >> Running 7.0.1 under Amazon Linux. I use the "basex" script to create a > >> new user. If I then call basexclient or use a pHp client with the new > >> credentials, I get an access denied. It works fine after I restart the > >> service. Note that server is launched as a service using "basexhttp > >> -S". Could this make any difference? > >> best > *P > > > On 11/2/11 4:37 PM, Christian Grün wrote: > > Hi Pascal, > > > >> Just started to configure various user accounts. Does the server need a > >> restart in order for new accounts to be recognized? > > new user accounts are instantly activated. > > > >> Also, I would recommend the default privileges to be none or read at > >> best. New accounts should not be able to write to the DB by default. > > That could be changed pretty easily; what do others think? > > Christian > > >

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BaseX-Talk November 2011