ETL or Extract Transform Load: Definition and use

With the advent of Big Data, companies are collecting more and more data. Over the past few years, the democratization of ETL software has enabled them to extract, transform and load this data into their data warehouses for better analysis. Let’s take a look at how this software works and at the different players on the market.

What is ETL ?

ETL processes first appeared in the 1970s. At that time, companies began to collect data from a variety of sources. ETL software was born to meet the need to integrate this diverse data.  Behind this acronym lie three essential steps in data management and business intelligence: Extract-Transform-Load, i.e. extracting data from the enterprise, transforming it, and loading it onto data warehouses. At the end of the process, ETL software must have been able to produce clean, easily accessible data that can be effectively exploited by analytics, business intelligence, and the company’s various business functions.

First step: data extraction

The first step in the ETL process is to extract raw data that has been collected by the company and may come from a variety of data sources: existing databases, logs concerning the company’s activity, unstructured databases relating to the behavior, performance, and anomalies of applications or other various operations. Data extraction enables data to be consolidated, processed, and refined, then stored in a centralized location before transformation. 

Second step: data transformation

Once the data has been extracted, the second step is to refine it. During this transformation phase, the data is sorted, structured, and cleaned: duplicate data is removed, missing values are eliminated, and all data is checked for consistency, usability, and reliability.

Third step: data loading

Data loading, or ‘Load’ as it is known in the Extract Transform Load process, simply means moving the sorted and cleansed data to a new storage space, the data warehouse, where it can be accessed and analyzed by all the company’s departments. In general, data warehouses support two modes of data loading: full loading and incremental loading. The latter will only take into account data that is different from that already present in the storage space.

The benefits of ETL software

All the steps in an ETL process can, of course, be carried out manually, but the margins for error are particularly wide. In the age of Big Data, companies are collecting ever more data, and for many, manual processing would require the mobilization of a large number of employees. An automated process enables better control of data, greater agility thanks to the centralization of the ETL process within a single software package, better sharing with the company’s various departments, and greater accuracy.

Who are the main players in the ETL market?

There are several proprietary and open-source solutions in the ETL software market. Among the best-known are BIRT, Cloudera, Pentaho, and Talend. Birt, which stands for Business Intelligence Reporting Tools, lets you create data visualizations and dashboards, which you can insert directly into your web platforms and customer reports. It’s an open-source solution, which means you can use its code to insert its modules into many other applications.  Cloudera, a second ETL solution, offers multi-functional analysis on a unified platform, eliminating silos and enabling more efficient data analysis.  In its data-sharing process, Cloudera focuses on security, data governance, and the production of consistent metadata. Flexible, it enables data to be deployed on a public cloud, a multi-cloud, and directly on-site. Previously known as Kettle, Pentaho is an Open Source software package that enables the design and execution of highly complex data manipulation and transformation operations. Pentaho is available in a free version, but the paid version offers far more functionality.  Last but not least, French company Talend is another major player in the market. It is the publisher of an Open Source software suite that has been around since 2005. Its ETL software is known as Talend Open Studio for Data Integration (TOS). This software enables data flow to be created intuitively, using a graphical interface. This integration solution is particularly appreciated for its ease of use, flexibility, and scalability. Talend’s software suite offers a range of tools for collecting, qualifying, processing, centralizing, and rendering your data. There are many solutions for extracting, transforming, and loading your data. ETL software, whether free or paid for, is generally designed to facilitate and secure data management and analysis. Given the evolution of corporate data collection, it’s a safe bet that the ETL market will continue to grow and that their functionalities will continue to evolve.