How to unmarshal large XML file

Question

I have a large (170 MB) XML document. The size is due to a complex tree structure that is an array. It's taking approximately 45 minutes to unmarshal the document into the OTD. Not sure if there's a way to process this XML document in pieces (logical section)?? Suggestions are appreciated.

Answer 1

I tried your suggestion, but get an error when I try to export the XSD node. It's expecting a TargetNamespace. Here is the beginning of the XSD that I imported:
<?xml version="1.0" encoding="utf-8"?>
<xs:schema elementFormDefault="qualified" xmlns:xs="http://www.w3.org/2001/XMLSchema">
<xs:element name="MeterReadingDocument" nillable="true" type="MeterReadingDocument" />
<xs:complexType name="MeterReadingDocument">
<xs:complexContent mixed="false">
<xs:extension base="XmlDocumentBase">
<xs:sequence>
<xs:element minOccurs="0" maxOccurs="1" name="Remarks" type="ArrayOfString" />
<xs:element minOccurs="0" maxOccurs="1" name="Header" type="ExportHeader" />
<xs:element minOccurs="0" maxOccurs="1" name="ImportExportParameters" type="ImportExportParameters" />
<xs:element minOccurs="0" maxOccurs="1" name="Channels" type="ArrayOfChannel" />
</xs:sequence>
</xs:extension>
</xs:complexContent>
</xs:complexType>
If I add a targetNamespace, then I get an exception when I attempt to unmarshal the file. I get the message:
There was an error during unmarshal.
Expect: '{http://www.w3.org/2001/XMLSchema}MeterReadingDocument', found: 'MeterReadingDocument'
Not sure what to do.
Thanks.