Yes, this is one way to do arrays. This approach emphasizes the use case where it is important to access individual elements via XML. There are two obvious down sides: 1. space: this will be >10 times the storage of the actual numbers. A big problem for many cases. 2. array algorithms (e.g., scatter-gather, transpose) do block operations which are totally ugly in this markup. A variant of this might mark up parts of the array, e.g., each row. Two other general approaches can be considered: Array as blob: markup says 'this is an array, laid out like so', data is a big blob. (Probably this is what Jim is talking about) Array as external blob: same as above, except payload is a URL, e.g., to OpenDAP server where the data is. (Ideal for "virtual datasets") The memo I was working on tries to lay these options out with the advantages and disadvantages. --- Robert E. McGrath National Center for Supercomputing Applications University of Illinois, Urbana-Champaign Champaign, Illinois 61820 (217)-333-6549 mcgrath@ncsa.uiuc.edu