Memory Usage in web service???

[Dave Stienessen]

Hi all,
I have a web service that (for better or worse) returns rather large
xmlDataDocument s (up to 150MB) I know - this is huge for a web service call,
but this is a service that's used by few users (less than 10) so I'd prefer
not to rip it apart right now - my question is can someone explain the
following memory usage

first, my code looks like (pseudo coded)
DataSet ds = getDataSet(); // memory usage of w3wp is at about 250MB after
this
XmlDataDocument oDoc = new XmlDataDocument (ds); // memory usage still at 250
MB
return oDoc; // executing this jumps w3wp to over 800 MB!!!


can someone please give me the reason why? Even if it copies the data to
stream it out, I wouldn't expect more than about 400-500MB of memory used???

Thanks
--
Dave Stienessen