Document order of nodes

All of the nodes in a hierarchy conform to an order, called document order, in which each node appears before its children. Document order corresponds to the order in which the nodes would appear if the node hierarchy were represented in serialized XML.

Nodes in a hierarchy appear in the following order:

• The root node is the first node.
• Element nodes occur before their children.
• Attribute nodes immediately follow the element node with which they are associated. The relative order of attribute nodes is arbitrary, but this order does not change during the processing of a query.
• The relative order of siblings is determined by their order in the node hierarchy.
• Children and descendants of a node occur before siblings that follow the node.