A method of implementing a tree data structure comprises creating a parent and child relationship between a first node and a second node, in which the first node and second node are at the same hierarchical level of the tree data structure, and maintaining only one incoming pointer for each of the nodes in the tree data structure at all times. A tree data structure in which each node in the tree data structure has a single incoming pointer, and in which the tree data structure comprises a pointer directed to a local overflow node from a node at the same hierarchical level as the local overflow node.