Thanks Gail!!! Now I understand what you are saying about the non-clustered index. However,asmall doubt remains as in the above example, as you said, if am trying to add RowID to the non unique clustered index,again there would be the same issue right?

Only thing is uqifier(4 bytes) can be replaced with RowID(bigint 8 bytes) , 4 bytes are again excess in all btree and leaf nodes of non-clustered indexes of the table...

Please correct me if am wrong.