Query more than two entity sets is a single call

Hi Folks,

I have created a gateway service using an RFC function module interface from ECC.

This RFC has four table parameters (A,B,C and D), out of which A is input, B,C and D are output.

The gateway model also has 4 entity sets(A,B,C and D).

I have specified associaiton navigation properties as follows.

Association:

A with B

A with C

A with D

Navigation:

A to B

A to C

A to D

I was about to redefine the method of 4 entitysets in the _EXT classes during when these questions arised

My questions:

Can I query B,C and D using a single http call?

or

While querying B can I fill C and D entity sets as well?

If yes how can I achieve it and if no what are my options?

Note: I cannot go for the option of making multiple calls to same RFC for getting the output in B,C and D entity sets.This will hit the performance of my application drastically.