As per the Postgres design, only the user who is owner of the Postgres's Cluster Directory ( which has permission 700 ) can own the Postgres daemon process.
But I have a requirement so that any other user belonging to the same group can also start the Postgres daemon. It might not be very difficult to change the code for this use case ( at least it seems to be ),
But could some one please suggest me whether this is advisable or I will be messing up with the design ( I am in particular worried about the shared memory ) .