Sparse heterogeneous data is often the type of data stored in NoSQL dbs. Modelled in a relational way, this produces many tables with many NULL fields, while keeping it in a key value format is neat and tidy.
I'd recommend the paper What Goes Around Comes Around[1], the first paper in Readings in Database Systems[2]
I'd recommend the paper What Goes Around Comes Around[1], the first paper in Readings in Database Systems[2]
[1] https://scholar.google.com/scholar?cluster=73661829057771494... [2]redbook.io