This paper describes a new schema-mapping technique for multi-tenancy called Chunk Folding, where the logical tables are vertically partitioned into chunks that are folded together into different physical multi-tenant tables and joined as needed. The database’s “meta-data budget” is divided between application-specific conventional tables and a large fixed set of generic structures called Chunk Tables.Interesting idea.
It is a clear weakness with most (if not all?) popular frameworks that they don't support multi tenancy (of hosted business services) in any way what so ever.