1. A method for execution by a processing module of a computer of a multiple computer dispersed storage network (MCDSN) that stores a plurality of data objects, the method comprises: determining to expand a hierarchical ordered index structure of a plurality of data object index entries, wherein the hierarchical ordered index structure is in accordance with an ordering of attributes of an attribute category, and wherein the plurality of data object index entries is stored in a multitude of data object level index nodes and is associated with the plurality of data objects; and when the hierarchical ordered index structure is to be expanded, entering a loop that includes: retrieving a root index node of the hierarchical ordered index structure from a set of MCDSN storage servers of the MCDSN; identifying immediate children index nodes of the root index node from entries of the root index node; dividing the immediate children index nodes into sets of children index nodes; creating, for each of the sets of children index nodes, a sub-root index node to produce a set of sub-root index nodes, wherein the sub-root index node includes entries for each child index node of the set of children index nodes; creating a new root index node to include entries for each of the sub-root index nodes of the set of sub-root index nodes; temporarily storing the new root index node and the set of sub-root index nodes in the MCDSN; when the root index node has not changed, updating the hierarchical ordered index structure with the new root index node and the set of sub-root index nodes; and when the root index node has changed, repeating the loop with the changed root index node being the root index node.