I've been playing around lately with SQL Data Services. Although (or perhaps because) I can knock out a well-structured relational database in my sleep, I'm struggling to get my head round how to design a performant database in an environment that has (for example) no enforcement of referential integrity and no indexes on columns other than the primary key.
Does anyone know of any guidelines?
Maybe a place to start would be how to create a many-to-many join that can be traversed from either side in a performant manner, even with vast numbers of rows entities?