Carbon footprint of an in-memory applicance

Question

Hi,
can you make any estimation on the carbon footprint, or performance/watt ratio,  of an in-memory database (or applicance)?
Keeping all data in memory, i.e. online,  could require more power than keeping only the data with frequent access and putting all other data on discs, i.e. offline.

Answer 1

It's an interesting question. I will just add my personal view.
First, in-memory databases use disks (or SSD) to persist data. There can also be a distinction between hot (always in-memory) and cold data (only read from disk to memory when needed). So just looking at "more memory uses more power" is not going to cut it.
Secondly, the a single SAP In-memory Appliance might be able to replace several traditional servers. For example, the next version could be used as a database server for SAP NetWeaver BW and replace a BW Accelerator appliance. Future versions of the in-memory appliance will consolidate database and application servers. Overall you will need less hardware i.e. consume less power.
Finally, power consumption of hardware components like CPUs and memory is basically being reduced with every new hardware generation. Since the in-memory appliance uses very current hardware (for example, Intel CPUs), it's save to assume that you get pretty energy efficient solutions.
In summary, I would say an in-memory solution has a significantly smaller footprint than comparable other solutions.
Regards,
Marc
SAP Techology RIG