To generate even numbers using transformer, we can make use of stage variables. declare a stage variable say SV1 and initialise it to 0. In the derivation of that stage variable increment it by 2 which looks like SV1+2. By doing this we can generate even numbers.
In transformer Properties, there is a tab called Surrogate Key. Here we can define it. We can select from a. Flat file : State file which holds the SK values and generates SK values. b. DB Sequence: Database sequence object to use to generate the SK values. oracle stage--->surrogate key generator--->transformer