A pre-relational databases datamodel. "Preceeded" by the relational model since the flexibility of this makes it hard to work with. Now re-invented in RDF :)
P. R, K. M, M. H, K. Venugopal, and L. Patnaik. International Journal of Innovative Science and Modern Engineering (IJISME), 3 (2):
67-74(January 2015)