1. A method for content indexing of streaming hierarchical document content, the method comprising: identifying a hierarchical node from a streaming hierarchical document, the streaming hierarchical document streamed in document order from an stored intact hierarchical document, the streaming hierarchical document comprising two or more namespace indicators, the hierarchical node associated with a first namespace indicator of the two or more namespace indicators; generating a first portion of a hierarchical pattern forest for the first namespace indicator using a first set of structured index path expressions, the hierarchical pattern forest comprising at least one of a tree and a twig generated from one or more structured index path expressions of the first set of structured index path expressions; comparing the hierarchical node to nodes of the first portion of the hierarchical pattern forest; matching the hierarchical node with an index node in one of a tree and a twig of the first portion of the hierarchical pattern forest, the index node having a path from an ancestor node to the index node that matches axis steps of at least one of the structured index path expressions for the first namespace indicator; storing an index entry for the hierarchical node in response to the determined match; identifying a second hierarchical node associated with a second namespace indicator; and generating a second portion of the hierarchical pattern forest for the second namespace indicator using a second set of structured index path expressions.