[Exist-open] java.lang.OutOfMemoryError ( DB too big? )

[Houman K. <kho...@we...>]

Hi There,

By now I am evaluating different XQuery solutions for my Master Thesis which
gets hopefully published by the end of this year.

I have a database with 2.3 Mio datasets and 3 columns.  I do a stress test
against SQL.

So far non of the XQuery solutions could handle the 230 MB XML file.  I
hoped that eXist worked better since at the same time it is a XML DB and an
XQuery solution, which should be more powerful.

Indeed in eXist; I can at least do a 'count' over this huge doc and get a
result back. (Not possible with other solutions yet)

But if I try other selects, I get a java.lang.OutOfMemoryError. (Like other
solutions)

(In this example I should get 2.3 Mio fields called 'ticks' which is an
integer value.)

for $wb in doc("/db/ippm/wisc_berkeley.xml")/RESULTS/ROW
return ($wb/ticks)


Other example: (Just the 'ticks; from August 1th, 2000)
(In this example I should get 80800 datasets but I still get a
java.lang.OutOfMemoryError)

for $wb in doc("/db/ippm/wisc_berkeley.xml")/RESULTS/ROW
where ($wb/ndate='20000801000000')
return ($wb/ticks)



In my opinion, if XQuery can't handle this huge amount of data it can't
compete against SQL.

Is it possible to tune up eXist?  

I tried it already myself to tune it up:
The startup.bat and client.bat have the parameter -Xmx256000k.
I start client.bat -l to query the information locally.

What else can be done?

I have tried it with eXist-1.0b1.jar and the newest version from the CVS.
I have a Pentium-M 1.7 GHz, 1 GB RAM.

I appreciate any help,
Regards
Houman M. Khorasani
University of Wisconsin Platteville