OutOfMemoryError with this schema

When I try to compile schema below, using XmlBeans.compileXsd as per javadoc for SchemaTypeSystem, I get an OutOfMemoryError.

<?xml version="1.0" encoding="UTF-8"?>
<xs:schema targetNamespace="http://www.orbeon.com/oxf/pipeline" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns="http://www.orbeon.com/oxf/pipeline" elementFormDefault="qualified" attributeFormDefault="unqualified" xsi:schemaLocation="http://www.w3.org/2001/XMLSchema http://www.w3.org/2001/XMLSchema.xsd">
<xs:element name="config">
<xs:annotation>
<xs:documentation>XPL root element</xs:documentation>
</xs:annotation>
<xs:complexType>
<xs:sequence>
<xs:element name="param" minOccurs="0" maxOccurs="unbounded">
<xs:complexType>
<xs:attribute name="name" type="xs:string" use="required"/>
<xs:attribute name="type" type="xs:string" use="required"/>
<xs:attributeGroup ref="p:debug-schema-attributes"/>
</xs:complexType>
</xs:element>
<xs:group ref="p:statements"/>
</xs:sequence>
</xs:complexType>
</xs:element>
<xs:group name="statement">
<xs:sequence>
<xs:choice>
<xs:element name="processor">
<xs:complexType>
<xs:sequence>
<xs:element name="input" minOccurs="0" maxOccurs="unbounded">
<xs:complexType>
<xs:sequence>
<xs:any processContents="lax" minOccurs="0"/>
</xs:sequence>
<xs:attribute name="name" type="xs:string" use="required"/>
<xs:attribute name="href" type="xs:string" use="optional"/>
<xs:attributeGroup ref="p:debug-schema-attributes"/>
</xs:complexType>
</xs:element>
<xs:element name="output" minOccurs="0" maxOccurs="unbounded">
<xs:complexType>
<xs:sequence>
<xs:any processContents="lax" minOccurs="0"/>
</xs:sequence>
<xs:attribute name="name" type="xs:string" use="required"/>
<xs:attribute name="id" type="xs:string" use="optional"/>
<xs:attribute name="ref" type="xs:string" use="optional"/>
<xs:attributeGroup ref="p:debug-schema-attributes"/>
</xs:complexType>
</xs:element>
</xs:sequence>
<xs:attribute name="uri" type="xs:anyURI" use="optional"/>
<xs:attribute name="name" type="xs:anyURI" use="optional"/>
<xs:attribute name="encapsulation" type="xs:string" use="optional"/>
</xs:complexType>
</xs:element>
<xs:element name="choose">
<xs:complexType>
<xs:sequence>
<xs:element name="when" maxOccurs="unbounded">
<xs:complexType>
<xs:group ref="p:statements"/>
<xs:attribute name="test" type="xs:string" use="required"/>
</xs:complexType>
</xs:element>
<xs:element name="otherwise" minOccurs="0">
<xs:complexType>
<xs:group ref="p:statements"/>
</xs:complexType>
</xs:element>
</xs:sequence>
<xs:attribute name="href" type="xs:string" use="required"/>
<xs:attributeGroup ref="p:debug-schema-attributes"/>
</xs:complexType>
</xs:element>
<xs:element name="for-each">
<xs:complexType>
<xs:group ref="p:statements"/>
<xs:attribute name="href" type="xs:string" use="required"/>
<xs:attribute name="select" type="xs:string" use="required"/>
<xs:attribute name="id" type="xs:QName" use="required"/>
<xs:attribute name="root" type="xs:QName" use="required"/>
</xs:complexType>
</xs:element>
</xs:choice>
</xs:sequence>
</xs:group>
<xs:group name="statements">
<xs:sequence>
<xs:group ref="p:statement" minOccurs="0" maxOccurs="unbounded"/>
</xs:sequence>
</xs:group>
<xs:attributeGroup name="debug-schema-attributes">
<xs:attribute name="debug" type="xs:string" use="optional"/>
<xs:attribute name="schema-href" type="xs:anyURI" use="optional"/>
<xs:attribute name="schema-uri" type="xs:anyURI" use="optional"/>
</xs:attributeGroup>
</xs:schema>