What is a staging area?Do we need it?What is the purpose of a staging area?

Staging area is place where you hold temporary tables on data warehouse server.

Staging tables are connected to work area or fact tables.

We basically need staging area to hold the data , and perform data cleansing and merging , before loading the data into warehouse.

In the absence of a staging area, the data load will have to go from the OLTP system to the OLAP system directly,which in fact can severely hamper the performance of the OLTP system.

This is the primary reason for the existence of a staging area. In addition, it also offers a platform for carrying out data cleansing.