What is the difference between SELECT * and selecting specific columns?

Parthiban Kannan

Updated on January 8, 2026

< 1 min read

SELECT * retrieves all columns from a table, including unnecessary ones.
Selecting specific columns pulls only the data required for analysis.
This improves query performance and reduces data transfer.
In my project, we avoided SELECT * in production queries.
We selected only business-relevant fields like order_id, date, and revenue.
It also makes queries easier to read and maintain.
Using specific columns helps control data exposure and security.