Difference between Database Testing and ETL Testing | SQL queries for ETL/Data Base Testing

- The main Objective of Database testing is check if the data is following the rules/standards defined in the Data Model.
- In Database testing , Data is organised in the database in the form of tables.
- DB testing includes verifying the components of database under test like schema, Functions, Stored Procedures, triggers, tables, underlying data, Performance etc.
- The main Objective of ETL testing is to check if the data moved properly as expected.
- ETL Testing covers testing of all these three steps involved in the ETL as well as testing the target database where in the data is loaded.

We will learn below topics in this article

Difference between Database testing and ETL Testing

Function	ETL Testing	Database Testing
Objective	Extraction, Transform and Loading for BI Reporting	Data validation and Integration
Systems applicable	Systems with historical data	Systems with more of transactional data
Database type	OLAP database for historical data	OLTP database for transactional data.
Data type	Denormalized data with a lot of indexes and aggregation	Normalized data consisting of a lot of joins.
Examples of tools	QuerySurge, Informatica	Selenium, QTP
Modeling	Multidimensional model	Entity-Relationship model
Operation	read-only option is used	create, read, update, and delete operations are performed
Data Size	Voluminous data	Data size used is small.
Volume	smaller scale.	Large scale.

Below are the top SQL queries/Concepts used in ETL testing.