Oracle today (Sep 21) announced a Database appliance which is a two server cluster with 24 cores of CPU, 96 GB memory per server and upto 12 TB of storage. In speculations of the Oracle Webcast today by Mark Hurd, Andy Mendelshon etc., the product was anticipated as Exadata mini or little brother of Exadata, targeted at the Mid-market (SMB), who either cannot afford Exadata or do not need one yet. This little brother weights 160 lbs!
The driving goal here is to keep the product simple and provide Oracle Appliance Manager. So finally Oracle uses the term "appliance" which is used to shy away from as Exadata was not meant to be plug and play. The interesting concept is that customers can license as many cores they want with some restrictions like same number of cores on each server (up to 24 in the box). I believe this is new to Oracle too. The CPU cores drive the cost of the Oracle RDBMs license usually so this can be game changing. The appliance runs Oracle Linux (OEL) and can used used as RAC. It can run one powerful DB instance or multiple say your Dev, Test and QA instances.
So how does it compare with Exadata entry level say 1/4 RACK? While a 1/4 RACK is 60 cores of CPU and 72 TB or storage, the DB appliance is only 24 cores (with ability to license a subset of those) and 12 TB of storage max. It is meant for up to 4 TB databases. Oracle will not license Hybrid Columnar Compression (HCC) or the Smart Scan with this box. Thus some of the "secret sauce" of the Exadata has been preserved. The DB appliance does come with the solid state disk (4 x 73 GB) for improving the redo performance.