What is the HANA database?

The SAP HANA database is an in-memory, column-oriented, relational database management system. It stores all data in-memory (RAM) and in a compressed columnar format. It is very fast; hence it does not require sums, indexes, materialized views, or aggregates. This reduces the database footprint. Everything is calculated on-demand and in the main memory. This makes it possible for companies to run online transaction processing (OLTP) and analytics applications (OLAP) on the same instance at the same time.