Talend interview questions

Introduction to Talend Interview Questions and Answers

Extraction, Transformation, and Load is the process used to convert the raw data into some useful information. It can be used for actionable business intelligence. Data is extracted from various sources such as Salesforce, SAP, and databases like RedShift and Oracle. It can also be extracted from file formats such as XML, CSV, AVRO, JSON, etc. This is then transformed and loaded Talend is an open source platform for data integration which provides various services and software for data management, data integration, data quality, enterprise application integration, Big data, and cloud storage. In this Talend Interview Questions article, we are going to discuss the interview questions for Talend.

Now, if you are looking for a job which is related to Talend then you need to prepare for the 2019 Talend Interview Questions. It is true that every interview is different as per the different job profiles. Here, we have prepared the important Talend Interview Questions and Answers which will help you get success in your interview.

In this 2019 Talend Interview Questions article, we shall present 10 most important and frequently asked Talend interview questions. These questions are divided into two parts are as follows:

Part 1 – Talend Interview Questions (Basic)

This first part covers basic Talend Interview Questions and Answers

Q1. Explain various connections available in Talend?

Answer:
The connections define if the data has to be a data output, processed or a logical sequence. Various connections are:

1. Row-based: Types such as Lookup, main, filter, ErrorRejects, Rejects, uniques/duplicates, Output, and Multiple Input/Output.
2. Iterate: This is used to perform a recurring loop on files which are contained in a directory.
3. Trigger: This connection is used to create a dependency between subjobs or Jobs which are triggered in a consecutive sequence. The two generalized categories are: Subjob and Component level triggers
4. Link: It is used to transfer the table schema into the ELT component.

Q2. How is Talend related to Code generator?

Answer:
This is the basic Talend Interview Question asked in an interview. Please find below the different tables that are supported by Talend are: Talend is called as a code generator which provides a user-friendly graphical user interface where the components simply need to be dragged and dropped for designing a job. Talent Studio automatically compiles into a Java class once the job is submitted where the inner components, begin, main and end help in the control flow and therefore it is also referred to as the code generator.

Q3. What schemas are supported by Talend?

Answer:
The following schemas are supported:

1. Generic schema: It is not tied to any particular source and also used as a sharable resource across different data sources.
2. Fixed schema: Read-only schemas which come predefined with some components.
3. Repository Schema: Schema is reusable and any changes made in the schema will be reflected in all the jobs.

Q4. What are routines?

Answer:
They are the reusable pieces of which can be used to optimize data processing by making use of custom code. It also helps in enhancing the Talend Studio features and also improves job capacity. There are basically two kinds of routines: User routine and System routine.

1. System routine: The read-only codes which can be directly called inside any Job.
2. User routine: Custom created a routine by the users either by making new ones or using the existing old ones.

Let us move to the next Talend Interview Questions

Q5. What is the difference between ETL and ELT?

Answer:
ETL or Extraction, Transformation, and Load is the age-old concept which involves the extraction of data from external sources, transforming it to make it fit for use as per business and operational needs, then loading it into end target data warehouse or target database. This is a very valid approach as long as there are multiple databases and source systems involved in the whole process. The data is transported from one place to another, so it is often advisable to do all the transformation related work in a separate specialized engine.
ELT, on the other hand, is the process where the extracted data is primarily loaded into the end systems. Thereafter, transformations are done on top of it. It is a better approach when your target system is efficient and robust enough to handle all the transformations. Most of the analytical databases today like Google Big Query and Amazon Redshift often make use of ELT technology because their end systems are efficient enough to process, tackle and handle all the transformed data.

Part 2 – Talend Interview Questions (Advanced)

Let us now have a look at the advanced Talend Interview Questions.

Q6. What is a sub job? How data is sent from the parent job to the child job?

Answer:
A sub job is defined as a single component or more than one component joined by a data flow. One job can at least have one sub job. Context variables should be used while passing a value from the parent to the child job.

Q7. Explain tMap component and also list down the different functions which can be performed by making its use?

Answer:
This is the most asked Talend Interview Questions in an interview. tMap is one of the essential components which forms a core part of the “processing” family. The main use is to map the input data with the output data. The main functions which can be performed by tap include:

1. Applying transformation rules on any kind of field.
2. Adding or removing columns
3. Reject data
4. Filter input and output data using constraints
5. Concatenate and interchanging of the data
6. Multiplexing and demultiplexing of data

Q8. Explain tDenormalizeSortedRow. Also, can we use Binary Transfer mode or an ASCII code in creating an SFTP connection?

Answer:
tDenormalizeSortedRow forms an integral component of the processing family. It is used to synthesize sorted input flow such that the memory is saved. All input sorted rows are combined in a group where the item separators are joined with distinct values. No, the transfer modes cannot be used while creating an SFTP connection. It is just an extension to SSH and therefore doesn’t support any kind of transfer modes.

Q9. Explain error handling in Talend?

Answer:
The following is the error handling process:

1. Exception throwing process can be relied upon which can also be seen in the run view of the red stack trace.
2. Every component and the sub job has to return the code which leads to additional processing. The OK/Error links can be used to redirect the error towards an error handling routine.
3. The best and the most trusted way to handle an error is to define an error handling subjob which gets called in case of an error.

Let us move to the next Talend Interview Questions

Q10. What is the difference between XMS and XMX parameters?

Answer:
XMS parameter is used to define the initial Heap size in Java whereas XMX is used to define the maximum heap size.

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Conclusion

Here we brought to you a list of 10 Talend interview questions and their answers. Don’t get limited to these as the interview is all about the practical and hand son experience which you have gained over a period of time. Stay tuned to our blog for more articles like these.

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