HANA is available in the Cloud as Infrastructure as a Service (IaaS), Platform as a Service (PaaS) and as an application platform (AaaS), and it is possible to buy all those options now, on a monthly basis, from the SAP Website.
For on-premise customers, HANA is licensed in one of two major ways:
First, is as a proportion of your Software Application value (SAV), just like you can license other databases from SAP. This could be for your whole estate, or for a specific product like BPC.
Second, is by the unit, which is 64GB of RAM. There are a few editions of HANA, depending on your need, that bundle other software and allow more, or less, restrictive usage. The pricing is tiered, depending on the number of units you buy, and accretive.
In all cases, HANA licensing includes a lot of functionality that you would pay extra for in other databases. For example, Dev, Test, HA, DR licensing are always included. And if you buy HANA Enterprise, you have access to all functionality at no additional cost – including Predictive Libraries, Spatial, Graph, OLAP, Integration and Web. HANA contains a huge amount of functionality that would require 20-30 different SKUs from Oracle.