What is ETL?
ETL abbreviates Extract Transformation Loading.
You see three terms which are Extract, Transform, Load and these three database functions combine and use ETL mechanism pulling the data from one database to another database with the help of tools such as Informatica.
So what we understand in here is ETL is Mechanism to perform following three functions.
- Extract is the process of reading data from a database.
- Transform is the process of converting the extracted data from its previous form into the form it needs to be in so that it can be placed into another database. Transformation occurs by using rules or lookup tables or by combining the data with other data.
- Load is the process of writing the data into the target database.
While testing we transfer data from sources to targets such as Dataware houses, Data Marts. During this process we will load data after cleansing and transforming using tool such as Informatica. And also ETL is used to convert databases from one format or type to another.