Need of an ETL Tool
Think of GE, the company has over 100+ years of history & presence in almost all the industries. Over these years company’s management style has been changed from book keeping to SAP. This transition was not a single day transition. In transition, from book keeping to SAP, they used a wide array of technologies, ranging from mainframes to PCs, data storage ranging from flat files to relational databases, programming languages ranging from Cobol to Java.This transformation resulted into different businesses, or to be precise different sub businesses within a business, running different applications, different hardware and different architecture. Technologies are introduced as and when invented & as and when required.
This directly resulted into the scenario, like HR department of the company running on Oracle Applications, Finance running SAP, some part of process chain supported by mainframes, some data stored on Oracle, some data on mainframes, some data in VSM files & the list goes on. If one day company requires a consolidated reports of assets, there are two ways.
- First completely manual, generate different reports from different systems and integrate them.
- Second fetch all the data from different systems/applications, make a Data Warehouse, and generate reports as per the requirement.
Obviously second approach is going to be the best.
Now to fetch the data from different systems, making it coherent, and loading into a Data Warehouse requires some kind of extraction, cleansing, integration, and load. ETL stands for Extraction, Transformation & Load.
ETL Tools provide facility to Extract data from different non-coherent systems, cleanse it, merge it and load into target systems.