Talend Interview Questions

21. Differentiate between OnComponentOk and OnSubjectOk ?
Answer : OnComponentOk and OnSubjectOk are trigger links which can connect to another subject job. Difference is that they both lies in the execution order of the connected subjobs.

22. What is the difference between the ETL and ELT?
Answer :
Extract, Transform, and load(ETL) is a process that involves extracting data from outside source, transforming it to fit operational needs (sometimes using staging tables), then loading it into the end target database or data warehouse. This approach is reasonable as long as many different databases are involved in your data warehouse landscape. In this scenario you have to transport data from one place to another anyway, so it’s a legitimate way to do the transformation work in a separate specialized engine.
Extract, Load, Transform(ELT) is a process where data is extracted, then loaded into staging table in the database, transforming it. Where it sits in the database and then loading it into the target database or data warehouse.

23. How the delimited data be normalized?
Answer : By clicking on the tNormalized component.

24. What is the use of Palette setting in talend?
Answer : This allow us to launch the studio more fastly because by using this only the current component is loaded in the project.

25. What is thew use of tLoqateAddressRow component in Talend?
Answer : This Component is used to correct mailing addresses associated with customer data to ensure a single customer view and better delivery for their customer mailings.

26. What’s new in v5.6?
Answer : This technical note highlights the important new features and capabilities of version 5.6 of Talend’s comprehensive suite of Platform, Enterprise and Open Studio solutions.
With version 5.6 Talend:
a. Extends it big data leadership position enabling firms to move beyond batch processing and into real-time big data by providing technical previews of the Apache Spark, Apache Spark Streaming and Apache Storm frameworks.
b. Enhances its support for the Internet of Things (loT) by introducing support for key loT protocols (MQTT, AMQP) to gather and collect information from machines, sensors, or other devices.
c. Improves Big Dta performance: Map Reduce executes on average 24% faster in v5.6 and 53% faster than in v5.4, while Big Data profiling performance is typically 20 times faster in v5.6 compared to v5.5.
d. Enables faster updates to MDM data models and provides deeper control of data lineage, more visibility and control.
e. Offers further enterprise application connectivity and support by continuing to add to its extensive list of over 800 connectors and components with enhanced support for enterprise applications such as SAP BAPI and Tables, Oracle 12 GoldenGate CDC, Microsoft HDInsight, Marketo and Salesforce.com

27. How we can store a string in an alphabetical order?
Answer : By using ALPHA routine with tJava component.

28. What is the use of tXML map operation?
Answer : With using this we are able to add various input and output flow as needed into the visual map editor to execute.

29. What are the operations which tMap allows?
Answer :
Data transformation on any type of fields.
Data multiplexing and demultiplexing.
Fields concatenation and interchange.
Data rejecting.
Field filtering using constraints.

30. Differentiate between ‘insert or update’ and ‘update or insert’.
Answer : Insert or update means first we insert a record, but if a record is matching with the primary key then the record is updated.
Update or insert means first we update the record with same primary and if the record doesn’t exists then we insert the record.