The concept of isolated ordered regions to maintain coordinates of nodes
is used by associating each node with coordinates relative to a
containing region. Modifications to nodes within a region only affect the
nodes in that region, and not nodes in other regions. Traversals that
retrieve information from the nodes can rebase the coordinates from their
containing region and return with a total order. Access patterns and
usage are used to recognize and prefetch pages. The probability of
revisiting traversed nodes are identified and pages in a bufferpool are
replaced based upon the identified probabilities (e.g., replacing pages
with the least probability of a revisit).