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  • Writer's pictureDuc Pham

ETL vs. ELT: Choose the Right Data Integration Strategy for Business Intelligence

In today's data-driven world, businesses have access to an ever-increasing amount of data that can be harnessed to make informed decisions. To transform raw data into actionable insights, Business Intelligence (BI) is crucial. ETL and ELT are two distinct data integration approaches that play a pivotal role in this process. In this article, we will explore the differences between ETL (Extract, Transform, Load) and ELT (Extract, Load, Transform) and help you determine which one is the better fit for your business intelligence needs.

ETL Data Extract

ETL - Extract, Transform, Load

ETL has been the traditional approach to data integration for decades. In ETL, data is first extracted from various source systems, then transformed to fit a specific data model or schema, and finally loaded into a data warehouse. This method has been popular for several reasons:

  1. Data Cleaning and Integration: ETL allows for extensive data cleaning, transformation, and enrichment before loading it into the data warehouse. This ensures data is accurate, consistent, and ready for reporting and analysis.

  2. Structured Data: ETL is well-suited for structured data sources and when a well-defined data model is in place. It is ideal for traditional relational databases and business intelligence tools that rely on pre-defined schemas.

  3. Historical Data: ETL is effective for managing historical data because it allows for integrating data from different sources into a single, structured format.

However, ETL has some drawbacks. It can be time-consuming, as data transformation and cleansing can be resource-intensive. Additionally, as data volumes grow, the process can become challenging to manage and maintain.

ETL Data Load

ELT - Extract, Load, Transform

ELT is a more modern approach to data integration, flipping the ETL process on its head. In ELT, data is first extracted from source systems and loaded into a data warehouse without significant transformation. Transformation and schema changes are performed within the data warehouse itself, using tools and technologies that can handle raw data efficiently. ELT has gained popularity for several reasons:

  1. Scalability: ELT is well-suited for handling large volumes of data, as it takes advantage of modern, distributed data processing platforms like Hadoop and cloud-based data warehouses.

  2. Speed: ELT can be faster than ETL because data is loaded into the warehouse quickly, and transformations can occur in parallel within the data warehouse, providing real-time or near-real-time access to data.

  3. Flexibility: ELT allows organizations to store raw data, making it easier to adapt to changing business requirements. Data can be transformed and modeled as needed, and users can explore and analyze raw data.

While ELT offers advantages in terms of scalability and speed, it is not without challenges. The lack of upfront data cleansing and transformation can lead to data quality issues, and it may require more resources to manage and optimize transformations within the data warehouse.

ETL Data Transform

Choosing the Right Approach for Business Intelligence

The choice between ETL and ELT depends on your specific business intelligence requirements:

1. Use ETL When:

  • You have well-structured, clean data sources.

  • You need to perform extensive data cleansing and transformation before analysis.

  • Historical data integration is critical.

  • You have a mature data warehouse and a fixed schema.

2. Use ELT When:

  • You deal with large volumes of data.

  • Real-time or near-real-time data access is required.

  • You want to store raw data for flexibility and future use.

  • Your data warehouse is built on a scalable, modern platform like a cloud-based solution.

It's also worth noting that some organizations opt for a hybrid approach, combining elements of both ETL and ELT to suit their specific needs.

Data integration in RocketBI

If you're using RocketBI to explore your business intelligence, should you use ETL or ELT? With a background in digital marketing, I'm a pro-ELT person since I need to deal with real-time analytics problems all the time. RocketBI can help you run ETL, ELT, or even hybrid for each data source. That's the flexibility that we give our users.

We will deep-dive into "How to do data integration with RocketBI" in another day. However, to give a simple picture, this is the streamlined step-by-step RocketBI's approach:

ETL in RocketBI:

  1. Extract - Data ingestion > Data source: Connect your data source.

  2. (Temporary Load) Data ingestion > Sync Jobs: Collect the data in the Data Warehouse with the incremental setting.

  3. Transform - Data management > Schema: transform the schema as you need, including encrypting sensitive data or removing unnecessary data in the same dataset

  4. Transform - Data management > Datacook: build a no-code data pipeline to process data from multiple datasets and sources. Remember to save time & resources, you should build this process with a limited date range. For example, transform only yesterday's data and run this automation daily.

  5. Load - Data management > Datacook: save the transformed dataset in a new dataset in your Data Warehouse with the append setting.

  6. (Temporary Data Cleanup) - Data management > Datacook: you should create another no-code ETL in Datacook to clean up the historical data synced to the original dataset. Make sure to leave some room for quick backup, like only deleting data that is more than 7 days old.

ELT in RocketBI:

  1. Extract - Data ingestion > Data source: Connect your data source.

  2. Load - Data ingestion > Sync Jobs: Collect the data in Data Warehouse. (Use incremental setting to save server resources)

  3. Done. Any Transformation you do, make sure to save it in a separate dataset and do not overwrite the original data.

In conclusion

When it comes to business intelligence, choosing between ETL and ELT depends on your data, infrastructure, and business objectives. Each approach has its advantages and disadvantages, so it's important to carefully consider your organization's specific requirements before making a decision. Ultimately, RocketBI empowers you to make effective data-driven decisions by supporting any data integration strategy you need to achieve your goals.

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