ETL Vs. ELT: What is the main difference?


In a nutshell, the differences between ETL and ELT can be summarized in this way: ETL converts data prior to loading it into your warehouse, while ELT transforms your data after it has been loaded in your data warehouse.

In this article, we’ll review the differences in operation between ETL and ELT to help with determining which one is most suitable for the data operations you currently are facing.

ETL is an acronym for “extract, transform, extract and load” and has been in use for a long time and is frequently considered to be the method that is most effective for collecting and reorganizing data into one format. On the other hand, since cloud data warehouses came into the picture, ELT, which stands for extract, load as well as transform, has become the most advanced method of connecting data.

It is crucial to be aware of the awareness of the fact that ETL and ELT each serve the same purpose; however, they differ in the method and how they’re implemented.

It is the identical three fundamental steps, regardless of whether you’re using ETL as well as ELT.

Extract: At this phase, which is the first step, you’ll be collecting information from all of your sources of data. The data you extract could be derived from structured relational databases as well as unstructured data sources such as emails and images. Both are feasible.

Transformation: At this phase, you’ll cleanse, process, and then convert the data into a format that can be saved in your data storage system in the format currently being used.

Load: The process that involves loading data into the destination storage and analyzing it with suitable business intelligence software. Analyze: This process involves analyzing the data loaded by using tools for business intelligence.

Which method do you think is optimal for you? The answer lies in the specifics of the methods required in etl vs elt.

What is ETL?

At first, when it was first introduced, the ETL procedure consisted of obtaining information from relational databases with the use of scripts written by hand. Nowadays, the majority of the time, this process is automated with professionally-designed ETL software, which is capable of extracting information from various sources and automating the process.

The benefits of using ETL

  1. The storage system you use is managed by your data warehouse. Are the systems you employ to store your data price-sensitive? In this case, using ETL might be able to aid you in reducing storage costs. ETL solutions can transform and filter data to ensure that you have only the information you require. This can reduce the requirement for storage space for data.

  1. Security protocols that are in compliance. It is possible that you are the laws regarding data privacy, such as GDPR SOC2, GDPR, and HIPAA, or regulations that are specific to your particular company. The requirements of these regulations often require you to erase or conceal sensitive data such as emails or IP addresses prior to storing the data within your database. It is easy to accomplish this through your ETL process by hiding or eradicating data at the transformation stage.

What exactly is ELT?

The process of transforming unstructured data like audio, photos, and video may take a considerable length of time. This could slow down the processing speed of the ETL process. This means that the data is initially saved to storage systems in order that transformations can be performed at any time they are needed.

The move to ELT is being aided significantly by cloud storage technology such as data warehouses or data lakes. These storage systems enable the storage of non-structured data and also the execution of data transforms in an efficient and thorough method.

The numerous advantages of ELT

  1. Fast: The ELT procedure doesn’t require any wait time at any stage during the process. The best ELT solutions immediately upload data into your data warehouse, and it’s waiting to be transformed by you.

  1. Transformable: Since they aren’t required to be defined prior to the start of process ELT process, you are able to effortlessly incorporate new and other information sources into the workflow.