storage in mem

too my understanding, postgres is now architected so that engine and
storage are ""splited""
and so one may think that storage code different that the
traditional postgres thing is possible.
I have heard of oracle like redo log things, ..etc

I wonder if a memory thing is on the way, somewhere ?

The why (1) of this question:
its quite easy, nowadays to find blades with 2 TB of RAM. (or even much
more !)

and, to my understanding (correct me if I am wrong !) postgres shared
buffers are not really efficient with "some" Terabyte of allocated space.

The why (2) I may have to do a POC with Sap HANA on one side and postgres
on the other
on machines with a lot of RAM.
so...
can someone shade some light ?

thanks,

Marc MILLAS
Senior Architect
+33607850334
www.mokadb.com