For a DMS, I want to replace MySQL with Cassandra to store file/folder nodes. Current I use adjacency list model to stores nodes hierarchy. The shortage of the adjacency list model is the expensive traversal cost. While I want to navigate the entire workspace or folder in hierarchy, I have to execute multiple queries (for each sub folder). In addition, special care must be taken when deleting nodes because of the potential for orphaning an entire sub-tree in the process (delete a folder and all of its children may be orphaned). How to design to store files/folders'node as tree structure in Cassandra?