In session properties There is an option

insert

update

insert as update

update as update

like that

by using this we will easily solve

By default all the rows in the session is set as insert flag you can change it in the session general properties -- Treate source rows as :update

so all the incoming rows will be set with update flag.now you can update the rows in the target table

hi

if ur database is teradata we can do it with a tpump or mload external loader.

update override in target properties is used basically for updating the target table based on a non key column.e.g update by ename.its not a key column in the EMP table.But if u use a UPD or session level properties it necessarily should have a PK.