How do you effectively manage the increasingly large and disparate data generated every day within your organization? Have you ever considered transforming your data once it's already in your data warehouse, rather than doing it before it gets there? That's where ELT comes in, a modern approach to data integration that is revolutionizing processing and analysis in today's IT environments, especially in cloud solutions. Today, companies must favor integration methods that value the performance, the flexibility, and a scalability increased.
ELT has become a key pillar in modern data management processes because it offers solutions to the limitations of the conventional ETL (Extract-Transform-Load) approach. Let's discover together what ELT is, how it works, and why it should perhaps become your preferred method for processing data.
ELT definition
THEELT, or”Extract, Load, Transform“(extract, load, and transform in French), is a data integration process where data is first extracted from its various sources and then loaded directly into the data warehouse. Only then are they transformed, using the computing power of the warehouse that allows massively parallel data to be processed.
Historical context and evolution
Traditionally, organizations used the ETL model to integrate their data, a three-step process: extraction, transformation, and loading. However, with the rise of cloud platforms, the scalability of modern data warehouses, and the demand for faster and more flexible solutions, ETL has evolved. The ELT model was therefore born to overcome these challenges while taking advantage of the growing capabilities of cloud infrastructures such as Google BigQuery, Amazon Redshift, and other cloud-based solutions.
How the ELT process works
Unlike the traditional ETL model where data is transformed before it is loaded, ELT reverses certain steps to rely on the computing power of modern data warehouses. Here is an overview of the ELT procedure.
Step 1: Data Extraction
The first phase, identical to ETL, consists of pullout raw data from a variety of sources, whether structured or not These sources can be databases, CSV files, SaaS solutions, customer relationship management systems, web services, etc. Extraction is generally done without prior transformation, which reduces the risks of information loss and allows data to be accessed more flexibly.
Step 2: Loading Data
The real difference is in this step: the extracted data is Loaded directly into the data warehouse without modification. In other words, the data arrives in its raw state, which allows for faster storage since we skip the complex and time-consuming phase of transformation. Modern cloud systems support this method particularly well by allowing almost infinite scalability.
Step 3: Data transformation
Once the raw data is loaded, it is transformed directly into the data warehouse using powerful built-in calculation engines, such as those from Google BigQuery or Amazon Redshift. This includes the standardization, the scrubbing, the filtering and other critical transformations before the data can be used for analysis. One of the key benefits of this method is that data transformation becomes an asynchronous process: you can delay some transformations until they are needed.
Expert advice: Transform only the data needed for analysis to maximize IT resources.
ELT vs ETL: understanding the differences
Comparing processes
Although ELT and ETL seem similar in their end goal — to make data ready for analysis — their processes differ considerably.
Advantages and disadvantages of each approach
The benefits of ETL
- Processing before loading : Ideal when the specifications of the transformed data are known in advance.
- Upstream data quality : Fewer useless data loaded into the warehouse.
- Wealth solutions : Suitable for traditional infrastructures.
The disadvantages of ETL
- Long processing time for large data sets.
- High cost in terms of storage and servers for transformations.
- Less flexible in a rapidly changing environment requiring frequent adjustments.
The advantages of the ELT
- Scalability : Especially suited to growing data volumes and cloud environments.
- Flexibility : Transformations can be adapted to demand.
- Infrastructure economy : No need for servers dedicated to transformations.
- Fast access to raw data for more diversified analyses and customized transformations.
The disadvantages of the ELT
- More complex management of raw data : Risk of overloading the warehouse with useless information.
- Requires skills in cloud warehouses modern to maximize its potential.
Specific use cases
- ETL : suitable for businesses that only want to load their data once it has been completely cleaned and transformed. Perfect for stable production environments where data patterns are predictable.
- ELT : ideal for businesses working with Big Data, requiring a real-time analysis or in the environments Cloud. Also optimized for organizations that need to analyze a variety of raw data sets.
ELT benefits
The advantages of ELT are numerous, especially in digital and massively data-driven environments.
Flexibility and scalability
Businesses can quickly load large amounts of raw data into their warehouses before adapting it to analytical models. Scalability of the cloud also makes it possible to adapt to fluctuations in data volumes, without requiring the upgrade of expensive equipment.
Cost reduction
By reducing the need for dedicated hardware for data transformation prior to loading, the ELT allows a business to save on infrastructure costs. By relying on the The power of cloud warehouses, this optimized model frees up expensive IT resources while significantly reducing operating budgets.
Performance improvement
The abilities of massively parallel processing cloud warehouses make it possible to transform data much more quickly than traditional systems. In other words, once data is in the warehouse, it can be transformed ready-to-use to meet a variety of analytical needs.
Access to raw data
With ELT, users can access untransformed raw data at any time. This is particularly useful when unexpected analyses or specific adjustments are required based on business needs, or in processes where unstructured data is exploited.
The ELT in the context of Cloud Computing
Integration with cloud technologies
Nature elastic and massively scalable cloud environments, such as Amazon Web Services (AWS), Google Cloud, and Microsoft Azure, make ELT an ideal model for cloud-native solutions. With services like BigQuery or Redshift, cloud infrastructure is replacing old, useless and expensive on-premise architectures.
Scalability and elasticity
Compute and storage capacities rubber bands of the cloud allow businesses to process growing volumes of data without constraint. The cloud intelligently distributes workloads to ensure optimal performance even in the event of traffic and processing spikes.
Reduced total cost of ownership (TCO)
The transition from on-premise architectures to infrastructure Cloud-first thanks to the ELT makes it possible to considerably reduce the total cost of ownership (TCO), especially for SMEs and fast-growing businesses. This way, you only pay for what you actually use, unlike physical infrastructures that require regular hardware updates.
ELT implementation challenges and considerations
Data security
Managing data in the cloud poses challenges, especially in terms of security And of confidentiality. Loading raw data into remote environments requires increased vigilance to prevent breaches and ensure that they are safe during processing.
Regulatory compliance
Businesses must ensure that the data manipulated through ELT processes respects the various local and international regulations, in particular in terms of personal data protection (RGPD, HIPAA, etc.).
Data governance
La data governance becomes crucial with the ELT, as storing large amounts of raw data can quickly become unmanageable if they are not properly labelled and classified. One rigorous strategy is required to ensure the quality and accuracy of the data.
Resource Management
Setting up and managing an ELT pipeline requires the right IT resources: a team that can manage modern warehouses, monitor transformation processes, and quickly resolve potential problems.
ELT tools and technologies
The growing adoption of the ELT has been accompanied by the development of numerous tools that facilitate its implementation and management within cloud environments.
Popular ELT platforms
Cloud platforms are now dominating the ELT market. Some of the best options include:
- Google BigQuery : a high performance cloud warehouse optimized for the ELT.
- Amazon Redshift : a popular solution offering rapid and efficient scalability of ELT treatments.
- Azure Data Factory : a cloud integration tool that simplifies the management and automation of data flows.
Integration with modern data warehouses
Modern data warehouses are designed to handle vast amounts of data with low latency. They take care of the treatment massively parallel (MPP) for optimal performance during the transformation stages, vital for an effective ELT process.
Open-source vs proprietary solutions
ELT tools are available in open-source solutions (like Apache NiFi and Airflow) and proprietors (like Fivetran, Stitch). While proprietary solutions often offer user-friendly interfaces accessible to non-technical users, open-source tools are preferred by businesses looking for maximum customization at a lower cost.
Use cases and concrete examples
ELT for big data
The ELT shines when it comes to dealing with large volumes of Big Data. The model makes it possible to quickly ingest massive data into cloud environments, where it is transformed on demand for complex analyses or data needs. Machine Learning.
ELT in real-time analysis
For businesses that want to monitor data sets in real time, ELT is more effective than ETL. By loading untransformed data continuously, analyses can be adjusted at a later time, according to Insights wanted.
ELT for Business Intelligence
The platforms of Business Intelligence benefit greatly from the ELT, as raw data is available at all times to support dynamic and predictive analytics. Tools like Table and Power BI can be easily integrated into ELT environments to generate dashboards in real time.
Concrete example : An SME in the e-commerce sector adopted the ELT to quickly load customer information into Redshift, then transform it for daily user engagement analyses. This flexible approach reduced analysis time from two days to a few hours.
Best practices for implementing ELT
Architecture design
To maximize the benefits of the ELT, it is crucial to design a robust architecture that takes into account the requirements of performances, in scalability And in security.
Optimizing performance
Use the transformative power of cloud warehouses to execute your transformations in parallel and at quiet times to avoid slowdowns.
Data quality management
Be sure to include measurements of quality control before and after each transformation to ensure the accuracy and reliability of the data delivered to analysts.
Monitoring and maintenance
Implement solutions of real-time tracking to automatically monitor and, if needed, adjust data pipelines, including storage and transformation stages.
The future of the ELT
Emerging trends
ELT will continue to grow as treatment in real time and the use of big data are becoming the norm in modern data analysis.
Integration with AI and Machine Learning
The ELT has a vital role to play in the applications ofartificial intelligence And of Machine Learning, where direct access to large quantities of raw data makes it possible to better train algorithms.
Changing data needs
With the continuous increase in volumes and diversity of data sources, the adaptive ELT will become an essential model for all businesses looking to gain in agility And in performance.
Conclusion
ELT is a modern, flexible, and scalable data integration approach tailored to meet growing data integration requirements. Big Data, real-time analysis and cloud technologies. It offers numerous advantages in terms of cost, performance, and ease of maintenance. However, each company must assess its specific needs before making a choice between ETL and ELT. For dynamic, cloud-based environments, ELT seems to be well-positioned to take the lead as an essential data integration process for years to come.