What is the difference between the ETL and ELT in Talend?

Hi sushant,

ETL

Traditionally, ETL refers to the process of moving data from source systems into a data warehouse. The data is:

Extracted – copied from the source system to a staging area
Transformed – reformatted for the warehouse with business calculations applied
Loaded – copied from the staging area into the warehouse
How these steps are performed varies widely between warehouses based on requirements. Typically, however, data is temporarily stored in at least one set of staging tables as part of the process. The extract step might copy data to tables as quickly as possible in order to minimize time spent querying the source system, or the transform step might place data in tables that are copies of the warehouse tables for ease of loading (to enable partition swapping, for example), but the general process stays the same despite these variations.

ELT

ELT is a different way of looking at the tool approach to data movement. Instead of transforming the data before it’s written, ELT leverages the target system to do the transformation. The data is copied to the target and then transformed in place.

ELT makes sense when the target is a high-end data engine, such as a data appliance, Hadoop cluster, or cloud installation to name three examples.