In today’s era, the demand for Database Warehouse testing is increasing very frequently. In the business world and IT industry, there are considerable opportunities in ETL Testing, because to protect data from and the daily maintenance of data is essential. ETL testing is required for day to day maintenance, integrity, and consistency of Data. From big business Enterprises to small-scale companies everyone wants to maintain their data integrity and consistency.

ETL means Extract, Transform, and Load.

What is ETL Testing?

ETL testing is done to make sure that the data which is loaded from source to the destination after the business transformation is accurate. In this type of testing, information is verified at various stages between the source and target destination.

ETL Testing Process

ETL Testing process is similar to all the other types of testing performed.

i) Analyzing requirements and data sources.

ii) Data acquisition

iii) Implement dimensional Modelling and business logic

iv) Populate and build data

v) Building Reports

Under ETL, We can Perform the Following Types of Testing:

1. Production Validation Testing

This testing is performed when data is being transferred into production systems. So it’s important to make sure that the data being transformed is validated completely before being turned to production.

2. Upgrades of Application

This type of testing validates the data being extracted to the new application or 0repository is the same as the data in a repository or old application. This type of ETL testing can be automatically generated, saving test development time

3. Metadata Testing

Basically in Metadata testing tester has to validate the source and target tables corresponding to documents.

4. Data Completeness Testing

To validate all the data is loaded to the target source is done in this type of testing. Testing like checking Aggregate functions, validating count is data completeness testing.

5. Data Accuracy Testing

This type of testing is done to check the accuracy of data being loaded and transformed

6. Data Transformation Testing

In this type of testing, the tester needs to run multiple SQL queries for each row to verify the transformation rules. It cannot be achieved by writing on one source SQL query and comparing the output with the target

7. Data Quality Testing

# Data Quality Tests checks the quality of syntax and reference tests. Data Quality testing is done to avoid any error due to the order number or date during the business process.

# Tests of Syntax: It reports dirty data, based on invalid characters, a character pattern, wrong upper or lower case order, etc.

# Tests of Reference: It will check the data according to the data model. For example Customer ID

# Data quality testing includes date check, number check, data check, precision check, null check, etc.

8. Incremental ETL testing

To validate the data integrity of old and new data with the addition of new data, this testing is done. All the inserts and updates are getting processed as expected during incremental ETL process are checked with this type of testing.

9. GUI/Navigation Testing

All the navigation or GUI aspects of the front end reports are checked with this type of testing

Importance of ETL Testing for Businesses

  • ETL testing assists in the procedure of verification, qualifying data and validation by avoiding information loss and duplicate records.
  • ETL testing services confluences information from various resources and morphs the data into a format that can be effective. Additionally, this permits the operator to access the data with ease from one interface itself, further reducing the dependability on your IT Team.
  • Besides validating the information, ETL Testing assists to create, monitor, and affirm the migrated/integrated information, data profiling, the data sources, data quality and meets the standards of data transformation rules and Performance Acceptance Criteria.
  • Not just this, ETL testing equipment increases IT productivity and streamlines the procedure of acquiring data from big data to magnify insights.
  • The ETL tool itself comprises strategies and protocols for deriving and monitoring data, eliminating the requirement for traditional programming tactics that are work focused and affluent. Therefore, ETL Testing is one of the most vital elements associated with big data testing of any business.
  • Further, ETL testing equipment has ingrained consistency with cloud data repositories, ERP and CRM podiums like Amazon Web Services, Salesforce, Oracle, NetSuite, Google Chrome, and several others.

Things To Look When You Are Hiring ETL Tester

  1. To test and execute all the backend driven data
  2. Create, design and implement test cases, test plans, and test harness
  3. Approve requirements and design specifications
  4. Identify the issues and provide solutions for potential problems
  5. To test data being transferred and flat files.
  6. To write and validate the SQL queries for the multiple scenarios
  7. To check the Performance with ETL performance testing.


For many enterprises, ETL is the challenge, but it is beneficial for the organization. It is necessary to protect your data from loss and keep updating the data daily. Data is a very crucial thing, and frequently changes in data warehouse increase the need for ETL Testing. It is necessary to clearly define the testing processes and security alliance between development, operations, and the business.


Ashima Sharma

Ashima is an ISTQB Certified QA Engineer associated with BugRaptors. She has expertise in web and mobile applications with the complete understanding of software Quality Assurance techniques and good knowledge of Software Development Lifecycle (SDLC) and Software Test Life Cycle (STLC). She has an excellent knowledge and working experience with test case creation, test case execution, test designs, and test result Analysis. She is Self-motivated, pro-active, task-oriented, and good team player.


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BugRaptors is one of the best software testing company headquartered in India and US, which is committed to cater the diverse QA needs of any business. We are one of the fastest growing QA companies; striving to deliver the technology oriented QA services, worldwide. BugRaptors is a team of 200+ ISTQB certified testers, along with ISO 9001:2018 and ISO 27001 certification.

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