What is the difference between data warehouse testing and conventional testing?

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.

Conventional testing is a sort of testing in which the test engineers will check the developed application or its related parts are working accordingly to the expectations of customer or not, from coding phase of SDLC to the end