Appendix D. Scaling for Many Child Nodes

The hierarchical database efficiently handles situations in which a single node has a large number (>100K) of child nodes. It does this by segmenting the parent's list of child references into multiple blocks, where each block is small enough to manage.

The hierarchical database actually performs this optimization in the background rather than do it during the Session's save() operation. As a consequence, the actual number of child references stored in any block might vary significantly from the "optimal" value. While the hierarchical database is capable of handling blocks of any size, performance when dealing with very large numbers of child nodes will be improved when the block sizes are optimized.