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Table of contents
1.
Introduction
2.
Informatica Basic Interview Questions
2.1.
1. What is Informatica PowerCenter?
2.2.
2. What are the components of Informatica?
2.3.
3. What are data types in Informatica?
2.4.
4. What is Lookup transformation?
2.5.
5. What is the meaning of Lookup transformation?
2.6.
6. Name the different types of ports that create the lookup transformations.
2.7.
7. How many repositories are created in the Informatica workflow manager?
2.8.
8. What do you mean by a domain?
2.9.
9. Can all mappings in the repository be validated simultaneously?
2.10.
10.  Explain the Aggregator transformation.
2.11.
11. How are duplicate rows deleted from flat files?
2.12.
12. What is the phrase Staging Area?
2.13.
13. List the use cases of Informatica?
2.14.
14. What are mapplets?
2.15.
15. Explain the difference between Informatica and DataStage.
2.16.
16. What is the role of a repository manager?
2.17.
17. What are data-driven sessions?
2.18.
18. What is the target load order?
2.19.
19. Differentiate between Mapping and Mapplet.
2.20.
20. Explain the difference between active and passive transformation.
2.21.
21. Explain the code page compatibility.
2.22.
22. How do pre-session and post-session shell commands function?
2.23.
23. How many input parameters can exist in an unconnected lookup?
2.24.
24. Describe Expression transformation.
2.25.
25. What is Joiner transformation?
3.
Informatica Interview Questions for Experienced
3.1.
26. Differentiate between Informatica and Talend.
3.2.
27. What do you mean by filter transformation?
3.3.
28. What methods or techniques can be employed to filter rows in Informatica?
3.4.
29. Differentiate between a database, a data mart, and a data warehouse.
3.5.
30. How is Union Transformation used?
3.6.
31. What do you mean by Incremental Aggregation?
3.7.
32. Explain the differences between the Target Designer and Target Load Order.
3.8.
33. What are the types of lookup transformation?
3.9.
34. Explain the differences between STOP and ABORT.
3.10.
35. What is “SUBSTR” in Informatica?
4.
Informatica Scenario-Based Interview Questions
4.1.
36. How can we handle a situation where a source system is sending duplicate records in Informatica?
4.2.
37. How can we ensure data quality when moving data from multiple sources in Informatica?
4.3.
38. What do we do if a workflow in Informatica fails at a certain session due to a database connection error?
4.4.
39. How can we improve the performance of an Informatica mapping that processes millions of records?
4.5.
40. What approach do we have to take if our session fails due to insufficient disk space during processing?
4.6.
41. How can we implement CDC (Change Data Capture) in Informatica?
4.7.
42. How do we handle slowly changing dimensions (SCD) in Informatica?
4.8.
43. How can we migrate an Informatica repository from one environment to another?
4.9.
44. What steps do we have to take if a lookup transformation is causing performance issues?
4.10.
45. How can we handle a requirement to load only the first ‘n’ records from a source file in Informatica?
5.
Tips to Prepare for Informatica Interview
6.
Frequently Asked Questions
6.1.
How can I prepare for an Informatica interview?
6.2.
What are the 4 tools of Informatica?
6.3.
What all types of cache are used in Informatica?
6.4.
Is Infomatics interview preparation hard?
7.
Conclusion 
Last Updated: Sep 29, 2024
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Informatica Interview Questions

Introduction

Informatica is an American software development company founded in 1993. It has its headquarters in Redwood City, California. Informatica is a leading software company specializing in data integration, quality, management, and cloud solutions. Established in 1993, Informatica provides various tools designed to help organizations manage, integrate, and transform vast amounts of data from various sources into useful insights.

The most well-known product of Informatica is Informatica PowerCenter, a powerful data integration platform widely used for extract, transform, and load (ETL) processes. It enables businesses to aggregate, cleanse, and move data between different systems, making it essential for data warehousing and business intelligence initiatives.

Top Informatica Interview Questions and Answer in 2023

We have collected a few Informatica interview questions that will help you crack the Informatica interview and land your dream job. These Informatica interview questions will also help in understanding various concepts of Informatica.

Informatica Basic Interview Questions

1. What is Informatica PowerCenter?

Informatica PowerCenter is a tool used for extraction, transformation, and loading (ETL) tool. These tools are used in building enterprise data warehouses. The components within Informatica PowerCenter help users to connect, fetch, and process data from various sources and transform it as per business requirements, and load it into a target data warehouse. Users can, for instance, connect to an Oracle or SQL Server database, or both, and integrate the data from two databases into a third system.

2. What are the components of Informatica?

 The components of Informatica includes:

  • PowerCenter Designer: A tool for designing and developing data integration mappings
     
  • PowerCenter Workflow Manager: A tool for scheduling and executing data integration workflows
     
  • PowerCenter Workflow Monitor: A tool for monitoring the execution of data integration workflows
     
  • PowerCenter Repository Manager: A tool for managing the Informatica repository, which stores metadata about data sources, targets, and mappings
     
  • Informatica Integration Service: A service that executes data integration mappings

3. What are data types in Informatica?

The data types in Informatica are:

  • Numeric: Integer, decimal, float, double
     
  • Character: String, char
     
  • Date and Time: Date, time, timestamp
     
  • Boolean: True, false
     
  • Binary: Binary data

4. What is Lookup transformation?

It is used to look up data in a relational table through mapping. Any relational database's lookup definition is imported from a source that has a tendency to connect clients and servers.

5. What is the meaning of Lookup transformation?

The primary use of Lookup transformation is to find the source qualifier, a target, or other sources to get the relevant data or information. Various types of files can be searched in the Lookup transformation. The multiple lookup transformations can be used in mapping and are compared with the lookup input port values.

6. Name the different types of ports that create the lookup transformations.

The different types of ports that create the lookup transformation are

  • Input port
  • Output port
  • Lookup port
  • Return port

7. How many repositories are created in the Informatica workflow manager?

In Informatica, the Repositories can be created in the workflow manager depending upon the required number of ports. 

8. What do you mean by a domain?

A domain is a collection of nodes and services which helps improve data management. It is a collection of resources and services that are managed as a single unit.

9. Can all mappings in the repository be validated simultaneously?

All the mappings in the repository cannot be validated simultaneously since each time, and it can only validate one mapping.

10.  Explain the Aggregator transformation.

It allows the execution of calculations involving sums, averages, and other aggregations. On the contrary, expression transformation allows for group calculations. 

11. How are duplicate rows deleted from flat files?

Duplicate rows in flat files can be deleted by comparing each row to others and removing any duplicates based on the data in the rows. Also, we can use the sorter transformation and a distinct option to delete duplicate rows.

12. What is the phrase Staging Area?

Transitory tables associated with the workspace or reality tables used to prepare information are in the organizing zone.

13. List the use cases of Informatica?

Informatica is a powerful tool that can be used to address a wide range of data integration and management challenges. By using Informatica, organizations can improve the quality, consistency, and accessibility of their data, which can lead to better business decisions and improved outcomes.

14. What are mapplets?

• It is a reusable object created in the Mapplet Designer

• It consists of a set of transformations and lets us reuse that transformation logic in multiple mappings

15. Explain the difference between Informatica and DataStage.

Below is a table that summarizes the key differences between Informatica and DataStage:

Feature Informatica DataStage
Comprehensiveness More comprehensive Less comprehensive
User-friendliness More user-friendly Less user-friendly
Cost More expensive Less expensive
Performance Good Excellent
Scalability Good Excellent
Flexibility Good Excellent
Customization Good Excellent

16. What is the role of a repository manager?

An administrative tool used to administrate and manage repository folders, objects, groups, etc., is a repository manager. 
A repository manager allows you to navigate multiple folders and repositories and manage groups and user permissions.

17. What are data-driven sessions?

When you set up a session with an update strategy, the data-driven session property instructs the Informatica server to use the instructions coded in the mapping to flag the rows for insert, update, delete, or reject. It can do it by mentioning “DD_UPDATE” or “DD_INSERT”, or “DD_DELETE” in the update strategy transformation.

18. What is the target load order?

Target load order generally specifies the order in which an integration service loads target tables. You can select a target load order based on the source qualifier transformations in a mapping. 

In Informatica, you can specify the order in which data is loaded into targets when multiple source qualifier transformations connect to various targets.

19. Differentiate between Mapping and Mapplet.

Mapping

Mapplet 

Mapping is a collection of source, target, and transformation. Mapplet is a collection of only transformation.
Mapping is developed with different transformations but is not reusable. Mapplet can re-use with other mapping and mapplets.
It is developed around what data move to the target and what modification is performed. It is developed for complex calculations used in multiple mappings

20. Explain the difference between active and passive transformation.

Transformation can be classified into two types:

Active transformation

Passive transformation

Here, the number of rows that pass from the source to the target is reduced as it eliminates the rows that do not meet the transformation condition. 

Additionally, it can change the transaction history or row type.

Unlike active transformations, passive transformations do not eliminate the number of rows, so all rows pass from source to target without being modified. 

Additionally, it can maintain the transaction boundary and row type.

21. Explain the code page compatibility.

Data loss cannot occur when data is moved between code pages, as long as both code pages use the same character set. The target page must contain all characteristics of the source page. 

Additionally, if all the characters of the source page are not present on the target page, then it would be a subset, and there will be loss of data loss during transformation as the two code pages are not compatible.

22. How do pre-session and post-session shell commands function?

For a session task, a command task can be called a pre-session or post-session shell command. The user can run it as the pre-session command, post-session command success, or post-session command failure. 

The application of the shell commands can be changed or modified based on use cases.

23. How many input parameters can exist in an unconnected lookup?

Various numbers of input parameters can exist in an unconnected lookup. For example, you can provide input parameters like column 1, column 2, column 3, column 4, and so on. But every time, the return value will be one.

24. Describe Expression transformation.

In this form of transformation, values can calculate in a single row before writing on the target. It can use to carry out non-aggregate calculations. Before output results are sent to the target tables, conditional statements can also be tested.

25. What is Joiner transformation?

While a source qualifier transformation can combine data from a common source, a joiner transformation combines two affiliated heterogeneous sources located in different locations. 

Informatica Interview Questions for Experienced

26. Differentiate between Informatica and Talend.

Informatica

Talend

It provides only commercial data integration. It has available open-source and commercial editions.
It was founded in 1993. It was founded in 2006.
Here, charges are applicable per customer. Open source is for free.
Metadata generated is stored in the RDBMS repository. It is implemented on any platform that supports java.
Here, integrating code is not effective. Code customization is effective.
Here, no prior knowledge is required. It is preferred to know java.
Here, automated deployment is not up to the mark. Here, the deployment is made easy.
Here, transformations are re-usable. Here, components are reusable.

27. What do you mean by filter transformation?

It serves as a medium for filtering rows in a mapping. Before applying a filter condition, data must first be transformed using a filter transformation.
Rows that meet the requirement can only pass via the filter because it contains all input/output ports.

28. What methods or techniques can be employed to filter rows in Informatica?

There are two main methods for filtering rows in Informatica:

  • Filter Transformation: The Filter transformation is a transformation that allows you to filter rows based on a specified condition. The filter condition can be any expression that returns a Boolean value
     
  • Lookups: Lookups can also be used to filter rows. When you use a lookup, you are comparing the data in one table to the data in another table. If the data matches, then the row is passed through the lookup. Otherwise, the row is rejected

29. Differentiate between a database, a data mart, and a data warehouse.

Database

Datamart

Data Warehouse

The database includes a set of sensible data.

Compared with a data warehouse, its affiliated data is normally small. 

Datamart is also a set of data designed to cater to the needs of different domains.

For example, an organization has a different set of data for its various departments, i.e., sales, finance, marketing, etc.

Data warehouse includes the assortments of all sorts of data. 

Here the data is taken out according to the customer's needs only. 

 

30. How is Union Transformation used?

It is a diverse input group transformation that may be used to combine data from different sources. It works like “UNION” All statement in “SQL” that is used to combine the result set of two “SELECT” statements.

31. What do you mean by Incremental Aggregation?

When a session is created for a mapping aggregate, the option for incremental aggregation is enabled. In order to perform incremental aggregation calculations incrementally, Power Center uses historical cache data and mapping to perform incremental aggregation.

32. Explain the differences between the Target Designer and Target Load Order.

Information target characterization is done using a target designer.

The server uses Target Load Order to characterize the request in which the information is to be stacked at an objective when there are various sources or a solitary source with numerous parcels connected to multiple focuses through the “INFORMATICA” server.

33. What are the types of lookup transformation?

There are four types of lookup transformation:

  • Relational or flat-file lookup: Relational lookup performs a lookup on relational tables.
     
  • Pipeline lookup: Pipeline lookup performs a lookup on application sources.
     
  • Connected or unconnected lookup: The unconnected lookup transformation occurs when the source is not connected, whereas the connected lookup transformation accepts data from the source, performs a lookup, and returns the result to the pipeline. 
     
  • Cached or uncached lookup: Lookup transformation can configure to cache lookup data, or we can directly query the lookup source whenever a lookup invokes.

34. Explain the differences between STOP and ABORT.

STOP

ABORT

The incorporation administration stops only perusing the information in the information source. 

Still, it keeps preparing and composing it to the objective when the “STOP” command is raised and runs on the session task.

The joining administration prevents perusing, preparing, and composing information to the objective via the “ABORT” command. 

It has a 60-second break time to complete handling and managing data through incorporation administration; otherwise, it kills the meeting.

 

35. What is “SUBSTR” in Informatica?

SUBSTR is a function that takes a string and extracts a certain number of characters starting at a predetermined position. Within PowerCenter mappings, it is used for the manipulation of string data.

Informatica Scenario-Based Interview Questions

36. How can we handle a situation where a source system is sending duplicate records in Informatica?

In this scenario, we can use the Sorter Transformation to eliminate duplicates. Set the Distinct option in the Sorter Transformation to true. This will allow it to only pass unique rows. Alternatively, we can use an Aggregator Transformation by grouping the records based on key fields and using it to filter out duplicates.

37. How can we ensure data quality when moving data from multiple sources in Informatica?

To ensure data quality, we can leverage Informatica Data Quality (IDQ) tools. We can also use transformations such as Expression and Filter Transformations to validate and cleanse data. We can also apply lookup transformations to verify and standardize reference data, as well as implement error-handling mechanisms to catch and handle invalid or inconsistent data.

38. What do we do if a workflow in Informatica fails at a certain session due to a database connection error?

If a workflow fails due to a database connection error, the following steps can be taken:

  1. Check the session logs to confirm that the error is related to a database connection.
  2. Verify the database connection settings in the Informatica Workflow Manager.
  3. If the issue is transient, you can configure the session to automatically retry the connection.
  4. For persistent issues, coordinate with the database team to resolve connectivity problems.

39. How can we improve the performance of an Informatica mapping that processes millions of records?

To enhance performance, we can:

  1. Use Partitioning to process data in parallel.
  2. Minimize data movement by performing joins, filtering, and aggregations in the source database (pushdown optimization).
  3. Reduce transformation complexity and avoid unnecessary lookups.
  4. Increase the buffer size in session properties to optimize memory usage.

40. What approach do we have to take if our session fails due to insufficient disk space during processing?

We can take below-mentioned steps if our session fails due to insufficient disk space during processing:

  1. Identify the root cause by examining the session logs and verifying disk space availability.
  2. Increase the available disk space in the directory where temporary or session files are stored.
  3. Consider using the Aggregator cache and Joiner cache settings to optimize space utilization, or change the cache directory to a disk with sufficient space.

41. How can we implement CDC (Change Data Capture) in Informatica?

We can implement Change Data Capture (CDC) in Informatica using various methods:

  1. Using a date/time stamp column in the source table to filter only the changed or new records.
  2. Implementing Informatica PowerExchange to capture changes from sources like databases or mainframes.
  3. For databases with CDC capabilities, Informatica can directly pull incremental changes by connecting to the CDC tables.

42. How do we handle slowly changing dimensions (SCD) in Informatica?

Informatica provides built-in support for handling Slowly Changing Dimensions (SCD):

  1. SCD Type 1: Overwrite the existing data with new data by updating the target records.
  2. SCD Type 2: Maintain historical data by adding new records with versioning or effective date columns.
  3. SCD Type 3: Store a limited history by updating specific columns in the target to track changes (e.g., current and previous values).

43. How can we migrate an Informatica repository from one environment to another?

To migrate an Informatica repository:

  1. Use the Repository Manager to export the required objects (mappings, workflows, etc.) from the source environment.
  2. Import these objects into the target environment.
  3. Verify that the connections, parameters, and variables are updated according to the target environment’s settings.
  4. Run test sessions in the target environment to ensure successful migration.

44. What steps do we have to take if a lookup transformation is causing performance issues?

To optimize a Lookup Transformation:

  1. Use connected lookups where possible to minimize overhead.
  2. Enable caching for lookups and ensure that the cache size is appropriately configured to prevent cache overflow.
  3. If the lookup table is large, apply filtering conditions at the database level to minimize the data being loaded into cache.
  4. Consider using SQL Override to improve the efficiency of the lookup query.

45. How can we handle a requirement to load only the first ‘n’ records from a source file in Informatica?

In Informatica, we can load only the first 'n' records by using the Rank Transformation. Configure the Rank Transformation to assign a rank to each row and filter out all records greater than 'n'. Alternatively, we can use a Filter Transformation and a Sequence Generator to limit the rows based on the sequence number.

Tips to Prepare for Informatica Interview

Preparing for an Informatica interview requires a strategic approach to mastering both technical and scenario-based questions. Here are some tips to help you succeed:

  1. Understand Core Informatica Concepts
    Make sure you have a solid understanding of fundamental concepts such as ETL (Extract, Transform, Load), Informatica PowerCenter architecture, data warehousing, and different types of transformations like Lookup, Aggregator, Joiner, and Sorter.
     
  2. Practice Scenario-Based Questions
    Interviewers often present real-world scenarios where you'll need to solve problems using Informatica tools. Practice scenarios involving data quality issues, performance tuning, error handling, and ETL process optimizations. This will help you become comfortable with applying Informatica functionalities in practical situations.
     
  3. Know Different Transformations
    Be prepared to discuss the various types of transformations used in Informatica, such as Source Qualifier, Expression, Router, Update Strategy, and Filter Transformations. Understanding how and when to use each transformation is crucial for answering scenario-based questions.
     
  4. Get Hands-On with Projects
    Work on actual projects or lab environments to understand how to handle real-time challenges. Try building mappings, workflows, and sessions that handle large datasets, complex data integration, and data quality rules.
     
  5. Learn Performance Tuning Techniques
    Performance tuning is a key aspect of Informatica. You should be familiar with techniques like partitioning, pushdown optimization, increasing buffer size, and optimizing lookup caches to improve the performance of your ETL jobs.
     
  6. Review Data Management Concepts
    Apart from mastering Informatica tools, make sure you understand general data management concepts like slowly changing dimensions (SCD), change data capture (CDC), data quality, and master data management (MDM). These topics often come up in interviews.
     
  7. Stay Updated with Latest Features
    Informatica constantly evolves, especially with its cloud offerings like Informatica Intelligent Cloud Services (IICS). Be sure to stay updated on the latest features, enhancements, and integration capabilities that Informatica provides.
     
  8. Prepare for Integration and Data Governance Questions
    Be prepared to explain how Informatica integrates with other tools, databases, or systems, especially in cloud and hybrid environments. Additionally, understand concepts related to data governance and how Informatica can be used to maintain data quality and compliance.
     
  9. Understand Error Handling
    Knowing how to handle and log errors during ETL processes is essential. Be familiar with Informatica’s error handling features like session logs, reusable error logs, and recovery mechanisms for failed sessions.
     
  10. Mock Interviews and Practice Tests
    Take part in mock interviews or online practice tests. This will help you get comfortable with the format of questions and identify areas where you may need more preparation.

Frequently Asked Questions

How can I prepare for an Informatica interview?

To prepare for an Informatica interview, research the company and its products, review common interview questions, and practice your skills. Be prepared to discuss your data integration, data quality, and data governance experience.

What are the 4 tools of Informatica?

The four main tools of Informatica are PowerCenter, PowerExchange, Data Quality, and Master Data Management. Data integration is handled by PowerCenter, external system integration by PowerExchange, data quality is used to profile and clean up data, and master data management is used to manage and control master data.

What all types of cache are used in Informatica?

The four cache types used by Informatica are Lookup, Dynamic Lookup, Static, and Persistent. Data from lookup tables are stored in lookup caches, dynamic lookup caches dynamic lookup data, static cache stores static data, and persistent cache stores reusable data.

Is Infomatics interview preparation hard?

Although preparing for an Informatica interview can be difficult, but it is manageable with some planning.

Conclusion 

In this article, we have discussed Informatica Interview Questions. Informatica remains a powerful and widely used data integration tool, and securing a role in this domain requires both technical proficiency and the ability to solve real-world data challenges. The Informatica interview questions aim to help you prepare comprehensively for your interview. 

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