Is it possible to perform some computations within the RAM?

Question

Theoretically, is there any way to perform any computations within the RAM, using memory related instructions such as move, clflush or whatever, su

Answer 1

Amazingly, yes, as per Paul R's comment: mov is Turing complete.

Such a mov only computer would be (highly) impractical however. not to mention the fact that it would be fiendishly hard to write a compiler for it. There is a c compiler that translates general purpose c programs into x86 mov instructions. Amazingly it does allows floating point calculations.
Because it is based on a Turing machine and not a Von Neumann computer it is horribly slow, (but it's a great way to obfuscate your code :-1).

For all practical purposes you can only do calculations via registers.
AFIAK only movs takes 2 memory operands, every other instruction that accesses memory uses a constant or register operand in addition.

Rowhammer is not a calculation mechanism, because it is non-deterministic.
It's also a artefact of the way dram is implemented, cache memory does not suffer from this effect.