BizTalk XLANGMessage parsing

Hi,

I get polled records of a Table using TypedPolling operation of WCF SQL Adapter. The size of the XLANGMessage is around 200MB . I need to parse this message for Node count , selected Node.

When tried to use a statement like ,

public int GetNodeCount(XLANGMessage message, string xpath)

{

XmlDocument xdoc = (XmlDocument)message[0].RetrieveAs(typeof(XmlDocument));

……..

or even when using message[0].RetrieveAs(typeof(XmlReader));

I get OutOfMemeory Exception.

How are large XLANGMessages handled in utility classes used in BizTalk Orchestrations ?

Thanks,

Vinayak Kumashi