So, if I would wonder what is the purpose of this almost “hidden” feature called flash cache and were this came from (also see my post “Permanent Link to Oracle RDBMS 11gR2 – Flash Cache” Oracle RDBMS 11gR2 – Flash Cache), now I know. I didn’t have the chance to follow Mr. Ellison’s launch event, but reading Alex Gorbatchev’s blog post on the Pythian web site Unveiling the OLTP Oracle Database Machine & Exadata v2 is enough explanation in the “why” and “how”. Flash cache is one of the pillars that make the synergy with the Sun Exadata machine.
As Alex stated:
Exadata Storage Servers
Storage Servers are based on Sun Fire X4275. Again top of the shelf Intel Xeon 5500 Nehalem processors.
Capacity increased — SAS disks are 600 GB (+33%) and SATA disks are 2 TB which doubles what ODBM v1 offered. We all know that big disks are bad but that’s where Sun FlashWire technology comes into play with flash cache on the controllers (5+TB for the full ODBM).
This is what Ellison said about Flash cache:
“These are not Flash disks. Make no mistake — these are no Flash disks. This is a memory hierarchy made up of DRAM in our database servers and Flash in our storage servers with very sophisticated algorithms, not simple LRU — we know for doing a sequential scan, we don’t blow out the cache.”
I will be interested in what Larry has to say on his “traditional” Oracle Open World Thursday speech this year. Exadata on Sun will probably be “old news” on that date/day. No need for hidden secrets to be announced via big “X” banners. The topic should be good for a 15 minutes or so to fill his speech and I still keep thinking, that on that day, Larry at least will pull one big “fresh rabbit” out of his magical hat.
In the meantime: “Wow, 5TB of flash cache to play with…”
Marco, we haven’t seen each other for… what almost a year now? That’s probably a good enough reason to start misspelling my name. 🙂
OOW speech? Maybe SPARC related or TPC-C but hey… maybe it’s going to be MySQL!?
On the other hand, database news were last year so perhaps this year is the time for application server stuff and etc. I’m sure you wold like something XML-ish. 🙂