we capture all transaction happened on source in our target staging, we need a sequence value inserted in replication target to understand sequence of operations happened on the source record. this would be new column in target let us call "change_sequence" which is not present in source.
Ex: table a source
col1(bk) col2
1 32
table a target
col1(bk) col2 change_sequence change_action
1 1 1 I
1 2 2 U
1 32 3 U