The present invention provides a computer implemented method, an apparatus, and a computer usable program product for indexing data. A controller identifies a set of data to be indexed, wherein a set of data structure trees represents the set of data. The controller merges the set of data structure trees to form a unified tree, wherein the unified tree contains a node for each unit of data in the set of data. The controller assigns an identifier to the node for each unit of data in the set of data that describes the node within the unified tree. The controller then serializes the unified tree to form a set of sequential series that represents the set of data structure trees, wherein the set of sequential series forms an index for the set of data.