Introduction to ETL
ETL stands for Extract-Transform-Load and it is a process of how data is loaded from the source system to the data warehouse. Data is extracted from an OLTP database, transformed to match the data warehouse schema and loaded into the data warehouse database. Many data warehouses also incorporate data from non-OLTP systems such as text files, legacy systems and spreadsheets.
An ETL tool extracts the data from all these heterogeneous data sources, transforms the data (like applying calculations, joining fields, keys, removing incorrect data fields, etc.), and loads it into a Data Warehouse.
For example, there is a retail store which has different departments like sales, marketing, logistics etc. Each of them is handling the customer information independently, and the way they store that data is quite different. The sales department have stored it by customer’s name, while marketing department by customer id.
Now if they want to check the history of the customer and want to know what the different products he/she bought owing to different marketing campaigns; it would be very tedious.
The solution is to use a Data warehouse to store information from different sources in a uniform structure using ETL. ETL can transform dissimilar data sets into a unified structure. Later use BI tools to derive meaningful insights and reports from this data.
Scope as ETL Tester
Academic background of a software tester should be in Computer Science. A BTech/ B.E., MCA , BCA , BSc- Computers will land you a job easily.
If you do not hold any of these degrees than you must complete a software testing certification like ISTQB and CSTE which help you learn Software Development/ Test Life Cycle and other testing methodologies.
There are numerous choice in the job titles and any MNCs are looking to hire the best candidate with the knowledge of ETL testing. Your career progression will include the various roles, depending upon the years of experience you have:
- Manual Testers / QA Analyst
- Automation Testers
- Performance Tester
- ETL / DWH / DB developers
- Project Managers
- Business Analyst
- QA Analyst
- QA Team Coordinator
- Test Manager
- Senior Test Manager
Your career progression as a software tester (QA Analyst) in typical CMMI level 5 company will look like following but will vary from company to company
QA Analyst (Fresher) => Sr. QA Analyst (2-3 year experience)=> QA Team Coordinator (5-6 year experience> =>Test Manager (8-11 experience) => Senior Test Manager (14+ experience)
The Future of ETL Testing is very bright. ETL Tools like Informatica PowerCenter, IBM Infosphere Information Server, Oracle data Integrator, Microsoft SQL Server Integrated Service, SAS, etc. are in huge demand in the Industry and because of the popularity their scope will increase in the future.
Alternate Career Tracks as a Software Tester
- Automation Testing: As an automation Test Engineer, you will be responsible for automating manual test case execution which otherwise could be time consuming. Tools used IBM Rational Robot , Silk performer and QTP
- Performance Testing:As a performance test engineer, you will be responsible for checking application responsiveness (time taken to load, maximum load application can handle) etc. Tools used Web-load , Load-runner.
- Business Analyst: A major advantages Testers have over Developers is that they have end to end business knowledge.
We also provides the best ETL Testing Online Training will assist you to start the flying career in the world of ETL Testing.