Former SAP exec Dennis Moore offers a theory as to why SAP cares so much about in-memory DBMS. It’s to integrate business processes, because SAP has no other software layer good at doing same (via RDBMS2).

If […] SAP were to undertake a rewrite of its application server tier to replace all calls to a database with calls to “HassoDB” (the in-memory database that got so much attention at SAPPHIRE this week), SAP would have the ability to simultaneously event-enable its product essentially with little to no additional effort.

So basically it’s because Event Processing is practically free with IMDB. It’s a good thought, may show the way for some other apps as well.