Databases & Data Storage
ETL
Definition
ETL, which stands for Extract, Transform, and Load, is a data integration process that combines data from multiple data sources into a single, consistent data store which is loaded into a data warehouse or other target system.
Why It Matters
ETL is the process by which raw data is cleaned, standardized, and made ready for analysis. It is a fundamental process for populating data warehouses and enabling business intelligence.
Contextual Example
An ETL job might: 1. Extract customer data from a Salesforce system and a separate marketing database. 2. Transform the data by standardizing date formats and merging duplicate customer records. 3. Load the clean, consolidated data into a central data warehouse for reporting.
Common Misunderstandings
- A related concept is ELT (Extract, Load, Transform), where raw data is loaded into the target system (like a data lake) first, and then transformed. This is a more modern approach.
- ETL processes can be complex and time-consuming to build and maintain.