Just have a mapping with two sources and use a joiner to match them up. For performance reasons, both sources should be sorted by the join key and the sorted input option should be set on the joiner.
If the source(full snap) and target both are relational tables, you can identify new and changed records as follows. (Select 2,A.* from SRC A where A.Src_key In (Select Src_key From TGT) MINUS Select 2,A.* from TGT A ) UNION ( Select 1, A.* from SRC A where A.src_key not IN (Select SRC_KEY from TGT) ) 1-New records