Refresh live connection (why)??

Hi,

I'm having a hard time understanding the logic of the refresh functionality.

I use the gateway to connect live to both Tabular and Multidimensional cubes. 

Even though these connections are live I have the option of clicking "Refresh Now" on a dataset using one of these connections.

When i click refresh different things happens for the two type of connections....

For the Tabular connection I can se the "On Demand" refresh in the refresh history

For the multidimensional connection nothing shows up in the history.

How does this refresh work.... and why does it even exist for live connections?

Thanx

Nicolaj