https://github.com/medined/D4M_Schema provides a step-by-step introduction to the D4M nosql schema used by many organizations.

D4M is a breakthrough in computer programming that combines the advantages of five distinct processing technologies (sparse linear algebra, associative arrays, fuzzy algebra, distributed arrays, and triple-store/NoSQL databases such as Hadoop HBase and Apache Accumulo) to provide a database and computation system that addresses the problems associated with Big Data.