Briefly explaining, trying to extract these values/per xml file (where .xml files are ID), to map it to its corresponding values.
Imagine, you have 100s of customers, and each customer uses/needs 1000s of different "@name". These "@name" would be similar across customer, but few would be using some values, few customer some other. Trying to collect all this information and find, which "@name" is used by most customer and so on and so forth. There are few such use cases, this one being most generic.
On Thu, Nov 6, 2014 at 11:23 AM, Fabrice Etanchaud fetanchaud@questel.com wrote:
The solution depends on the usage you will have of your extraction.
May I ask you what is your extraction for ?
Best regards,
Fabrice
*De :* Mansi Sheth [mailto:mansi.sheth@gmail.com] *Envoyé :* jeudi 6 novembre 2014 17:11 *À :* Fabrice Etanchaud *Cc :* Christian Grün; BaseX
*Objet :* Re: [basex-talk] Out Of Memory
Interesting idea, I thought of using db partition, but didn't pursue it further, mainly due to below thought process.
Currently, I am ingesting ~3000 xml files, storing ~50 xml files per db, which would be growing quickly. So, below approach would lead to ~3000 more files (which would be increasing), increasing I/O operations considerably for further pre-processing.
However, I don't really care if process takes few minutes to few hours (as long as its not day(s) ;)). Given the situation and my options, I would surely try this.
Database, is currently indexed at attribute level, as thats what I would be querying the most. Do you think, I should do anything differently ?
Thanks,
- Mansi
On Thu, Nov 6, 2014 at 10:48 AM, Fabrice Etanchaud fetanchaud@questel.com wrote:
Hi Mansi,
Here you have a natural partition of your data : the files you ingested.
So my first suggestion would be to query your data on a file basis:
for $doc in db:open(‘your_collection_name’)
let $file-name := db:path($doc)
return
file:write($file-name,
<names>
{ for $name in$doc//E/@name/data()
return<name>{$name}</name>
}
</names>
)
Is it for indexing ?
Hope it helps,
Best regards,
Fabrice Etanchaud
Questel/Orbit
*De :* basex-talk-bounces@mailman.uni-konstanz.de [mailto: basex-talk-bounces@mailman.uni-konstanz.de] *De la part de* Mansi Sheth *Envoyé :* jeudi 6 novembre 2014 16:33 *À :* Christian Grün *Cc :* BaseX *Objet :* Re: [basex-talk] Out Of Memory
This would need a lot of details, so bear with me below:
Briefly my XML files look like:
<A name="">
<B name=""> <C name=""> <D name=""> <E name=""/><A> can contain <B>, <C> or <D> and B, C or D can contain E. We have 1000s (currently 3000 in my test data set) of such xml files, of size 50MB on an average. Its tons of data ! Currently, my database is of ~18GB in size.
Query: /A/*//E/@name/string()
This query, was going OOM, within few mins.
I tried a few ways, of whitelisting, with contain clause, to truncate the result set. That didn't help too. So, now I am out of ideas. This is giving JVM 10GB of dedicated memory.
Once, above query works and doesn't go Out Of Memory, I also need corresponding file names too:
XYZ.xml //E/@name
PQR.xml //E/@name
Let me know if you would need more details, to appreciate the issue ?
- Mansi
On Thu, Nov 6, 2014 at 8:48 AM, Christian Grün christian.gruen@gmail.com wrote:
Hi Mansi,
I think we need more information on the queries that are causing the problems.
Best, Christian
On Wed, Nov 5, 2014 at 8:48 PM, Mansi Sheth mansi.sheth@gmail.com wrote:
Hello,
I have a use case, where I have to extract lots in information from each
XML
in each DB. Something like, attribute values of most of the nodes in an
XML.
For such, queries based goes Out Of Memory with below exception. I am
giving
it ~12GB of RAM on i7 processor. Well I can't complain here since I am
most
definitely asking for loads of data, but is there any way I can get these kinds of data successfully ?
mansi-veracode:BigData mansiadmin$ ~/Downloads/basex/bin/basexhttp BaseX 8.0 beta b45c1e2 [Server] Server was started (port: 1984) HTTP Server was started (port: 8984) Exception in thread "qtp2068921630-18" java.lang.OutOfMemoryError: Java
heap
space at
java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject.addConditionWaiter(AbstractQueuedSynchronizer.java:1857)
at
java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject.awaitNanos(AbstractQueuedSynchronizer.java:2073)
at
org.eclipse.jetty.util.BlockingArrayQueue.poll(BlockingArrayQueue.java:342)
at
org.eclipse.jetty.util.thread.QueuedThreadPool.idleJobPoll(QueuedThreadPool.java:526)
at
org.eclipse.jetty.util.thread.QueuedThreadPool.access$600(QueuedThreadPool.java:44)
at
org.eclipse.jetty.util.thread.QueuedThreadPool$3.run(QueuedThreadPool.java:572)
at java.lang.Thread.run(Thread.java:744)
--
- Mansi
--
- Mansi
--
- Mansi