Extracting large amounts of data

Hi,

I have a reasonably sized database (500MB) all in one collection in 
Xindice. I would like to extract a single element from everyone of the 
many docs - the trouble is the client machine keeps running out of memory.
Here's the single element result of my query.

<xq:result xmlns:xq="http://xml.apache.org/xindice/Query"; 
xq:col="/rus/RUR" 
xq:key="2006-01-24T23:12:06Z:217674.master@xxxxxxxxxxxxxxxxxxxxxxx">PT00H00M00S</xq:result>
Is there any way I can stream the results to a file?  Are their better 
ways to extract large amounts of data, than using
     ResourceSet resourceSet = service.query(xpath);

What other strategies are available?  I've been thinking about perhaps 
splitting my database into smaller collections and aggregating the 
results from these...
Any pointers much appreciated,

Kind regards,

Matt Ford.