I'm looking for a little guidance in representing a file system -- well just the file and directory structure of a file system. Often articles on representing a hierarchy discuss the advantages of using Nested Sets (or nested intervals) it seems. I'm not clear how well they apply to a file system-like hierarchy, though. The examples (and my limited understanding) of Nested Sets have the leaf nodes at the end of the branches, where in a file system a node can have both leaf nodes (files) and branches (directories). Also, the Nested Sets seem to solve problems I don't have -- such as finding all descendants of a given node. My simple requirements are: -- Quickly be able to lookup content by a full "path" name -- Provide "directory" views that shows parent, list of contents including any "sub-directories". -- To be able to easily move branches. It will not be a large collection of "files" in the tree, so that's not an issue. Seems like an Adjacency List along with a de-normalized "path" column in the leaf nodes would meet the requirements. But, as I see nested sets discussed so often I wonder which is a better approach. I assume this is a reasonably common problem so I'm curious how others have implemented it. Thanks, -- Bill Moseley moseley@xxxxxxxx