Skip to main content

Interview questions on aggregator transformation in informatica - Part - 4


What is Incremental Aggregation?
 
Answer:
 
We can enable the session option, Incremental Aggregation for a session that includes an Aggregator Trans-formation. When the Integration Service performs incremental aggregation, it actually passes changed source data through the mapping and uses the historical cache data to perform aggregate calculations incrementally.



Sorted input for aggregator transformation will improve performance of mapping. How-ever, if sorted input is used for nested aggregate expression or incremental aggregation, then the mapping may result in session failure. Explain why?

Answer:
Interview questions on aggregator transformation in informatica - Part - 4
Interview questions on aggregator transformation in informatica - Part - 4
 
In case of a nested aggregation, there are multiple levels of sorting associated as each aggregation function will require one sorting pass, and after the first level of aggregation, the sort order of the group by column may get jumbled up, so before the second level of aggregation, Informatica must internally sort it again. However, if we already indicate that input is sorted, Informatica will not do this sorting - resulting into failure. In incremental aggregation, the aggregate calculations are stored in historical cache on the server. In this historical cache the data may not be in sorted order. If we give sorted input, the records come as presorted for that particular run but in the historical cache the data may not be in the sorted order.




How can we delete duplicate record using Informatica Aggregator?

Answer:
 
One way to handle duplicate records in source batch run is to use an Aggregator Transformation and using the Group By checkbox on the ports having duplicate occurring data. Here you can have the flexibility to se-lect the last or the first of the duplicate column value records.

Comments

Popular posts from this blog

Contact Me

Do You have any queries ?                   If you are having any query or wishing to get any type of help related Datawarehouse, OBIEE, OBIA, OAC then please e-email on below. I will reply to your email within 24 hrs. If I didn’t reply to you within 24 Hrs., Please be patience, I must be busy in some work. kashif7222@gmail.com

Top 130 SQL Interview Questions And Answers

1. Display the dept information from department table.   Select   *   from   dept; 2. Display the details of all employees   Select * from emp; 3. Display the name and job for all employees    Select ename ,job from emp; 4. Display name and salary for all employees.   Select ename   , sal   from emp;   5. Display employee number and total salary   for each employee. Select empno, sal+comm from emp; 6. Display employee name and annual salary for all employees.   Select empno,empname,12*sal+nvl(comm,0) annualsal from emp; 7. Display the names of all employees who are working in department number 10   Select ename from emp where deptno=10; 8. Display the names of all employees working as   clerks and drawing a salary more than 3000   Select ename from emp where job=’clerk’and sal>3000; 9. Display employee number and names for employees who earn commission   Select empno,ename from emp where comm is not null and comm>0. 10

Informatica sample project

Informatica sample project - 1 CareFirst – Blue Cross Blue Shield, Maryland (April 2009 – Current) Senior ETL Developer/Lead Model Office DWH Implementation (April 2009 – Current) CareFirst Blue Cross Blue Shield is one of the leading health care insurance provided in Atlantic region of United States covering Maryland, Delaware and Washington DC. Model Office project was built to create data warehouse for multiple subject areas including Members, Claims, and Revenue etc. The project was to provide data into EDM and to third party vendor (Verisk) to develop cubes based on data provided into EDM. I was responsible for analyzing source systems data, designing and developing ETL mappings. I was also responsible for coordinating testing with analysts and users. Responsibilities: ·          Interacted with Data Modelers and Business Analysts to understand the requirements and the impact of the ETL on the business. ·          Understood the requirement and develope