1、Exadata Brings In-Memory OLTP to Storage
- Exadata Storage Servers add a memory cache in front of Flash memory
- Similar to current Flash cache in front of disk
- Cache is additive with cache at Database Server
- Only possible because of tight integration with Database
- 2.5x Lower latency for OLTP IO – 100 usec
- Up to 21 TB of DRAM for OLTP acceleration with Memory Upgrade Kit
- Compare to 5TB of flash in V2 Exadata
Non-Volatile Memory Cache in Exadata Storage
- Exadata Storage Servers will add Non-Volatile memory cache in front of Flash memory – Intel 3D X-Point
- Add software for RDMA access for much lower latency
- RDMA direct access to NVRAM gives 20x lower latency than Flash
- NVRAM used as a cache effectively increases its capacity by 10x vs using NVRAM directly as expensive storage
- Expensive NVRAM shared across servers for lower cost
- NVRAM mirrored across storage servers for fault-tolerance