Informatica – Post/Pre Session Variable Assignment

February 25, 2014

Hello Friends, Time for some learning. This time i have taken up the Informatica Variables and Parameters which i am very much fond of 🙂

This time i have taken up something that i came across in one of the development my team was involved in, and there was a need to pass a value from one task/session to another as we had a check with respect to the value we get from one session to be used going forward in the process.


For instance, my requirement is to check on the count of records from session_1 and then to count on records in session_2 but with the same counter (increment from where the Session_1 count ended) ending up with the total count of records. Something like, i had 100 records in session_1 and then i have to count from there as 100+1 and so on for the session_2. Looks simple, but quite a nail biting and challenging experience while we try getting it in Informatica!!

And then we came across this approach/feature available in the Informatica ‘Pre-Session/Post-Session Variable Assignment’. Which was all about the assigning of Variable values between the Sessions and it’s Parent Worklet/Workflow and vice-versa. Interesting right? If not clear lets go with a step by step illustration for a better understanding on this.

1. All we need to do is define a Counter variable/Parameter $$v1_Count for the session_1, and then our session runs to populate $$v1_Count as a usual Mapping Variable/Parameter does.

2. Next is, to assign this value to the common Variable (that acts as an intermediate between two of our sessions) which will be the Parent Worklet/Workflow Variable defined as any other Variable in the Edit Workflow/Worklet Options. In my case i have Workflow variable $$wf_v_Count defined.

3. Now in the session_1, Components tab -> lets edit the “Post session Variable assignment” option (it can be on failure or on success),

(i) Post-session on success variable assignment
(ii) Post-session on failure variable assignment

and i define it as – “Parent_Workflow/Worklet_Variable = Mapping_Variable/Parameter”

i.e., $$wf_v_Count = $$v1_Count

So here we have the $$v1_Count value open for any task,session or Worklet under the same parent can take up and use it for processing.

4. In our case, for the next session_2, i have to go for Components tab -> “Pre Session Variable Assignment” to be defined to assign the value from the $$wf_v_Count to the respective session’s Mapping Variable/Parameter $$v2_Count.

So we define it as “Mapping_Variable/Parameter = Parent_Workflow/Worklet_Variable”

i.e., $$v2_Count = $$wf_v_Count

The same can be used all over the Parent Workflow/Worklet, in any decision tasks or on link conditions. Thus we have now passed on the value from one session to the other and can be processed thereafter. Hope this was an interesting and helpful piece to you.

Do post your comments on any corrections or queries with respect to this. Share this if it can help someone.


One Response to “Informatica – Post/Pre Session Variable Assignment”

  1. Pushpa Says:

    I have a doubt . Can u please clarify it,
    workflow which has two worklets in it. In the second Worlet., can we assign the first worklet prevtaskstatus to second Worlet variable in presession assignment and use it within work let .

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