Think of any big
organization, 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 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 logical 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.