you don't need RAC

http://www.my-idconcept.de/downloads/You_Probably_Dont_Need_RAC.pdf
RAC is very cool technology. But it’s expensive.
So let’s play around with Larry’s vision of cheap Intel-based Linux clusters. Let’s buy those two cheap, 4-cpu Intel boxes and put them together in a cluster with Oracle9i and RAC on top:
Price for the hardware: About US$15.000,- or so .
Price for the OS (Linux): About US$0.50,- or thereabout (it depends!)
Price for Oracle w/ RAC: US$480.000,-

So that’s half a million to Oracle. Put another way: It’s 1 dollar to the box movers for every 32 dollars Oracle gets.
Psychologically it’s hard for the customers to understand that they have to buy something that expensive to run on such cheap hardware. The gap is too big, and Oracle will need to address it soon.

There’s nothing like RAC on the market, but that doesn’t mean you have to buy RAC. I usually joke that it’s like buying a car for US$10.000,- that has all the facilities you need from a good and stable car. Airbags and ABS brakes are US$500.000,- extra, by the way. Well, airbags and ABS are wonderful to have and
they increase your security. But it’s a lot of money compared to the basic car price.