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Avoid use of anonymous derived types in XML schema definitions
Some XML Schema Definition (XSD) features (restrictions on the primitive string type, for
example) result in modifications to the type that require a new subtype to be generated. If
these types are not explicitly declared, a new subtype (a derived type) is generated at run
time. Performance is generally better if this situation can be avoided. Avoid adding restrictions
to elements of primitive type where possible. If a restriction is unavoidable, consider creating
a new, concrete SimpleType that extends the primitive type to include the restriction. Then
XSD elements might use that type without degraded performance.
Avoid references to elements in one XML schema definition from another
Avoid referencing an element in one XSD from another. For example, if A.xsd defines an
element, AElement (shown in Example 2-1), it might be referenced from another file, B.xsd
(shown in Example 2-2).
Example 2-1 AElement XSD
Example 2-2 AElement referenced from another file
This practice often performs poorly. It is better to define the type concretely and make any
new elements use this type. Thus, A.xsd takes the form shown in Example 2-3.
Example 2-3 AElementType XSD
The form that B.xsd takes is shown in Example 2-4.
Example 2-4 BElement XSD
Reuse data object type metadata where possible
Within application code, it is common to refer to types, for example, when creating a BO. It is
possible to refer to a BO type by name, for example in the method
DataFactory.create(String URI, String typeName).
You can also refer to the type by a direct reference, such as in the method
DataFactory.create(Type type). In cases where a type is likely to be used more than once,
it is faster to retain the type, for example, through DataObject.getType(), and reuse that type
for future use.
12 IBM Business Process Manager V8.0 Performance Tuning and Best Practices