DISTINCT & ALL: Overview

Use DISTINCT to remove duplicate rows

Apply DISTINCT with aggregates (COUNT DISTINCT)

Understand ALL keyword (default behavior)

Combine DISTINCT with multiple columns

Optimize DISTINCT queries for performance

Know when to use DISTINCT vs GROUP BY

Use DISTINCT to remove duplicate rows

Apply DISTINCT with aggregates (COUNT DISTINCT)

Understand ALL keyword (default behavior)

Combine DISTINCT with multiple columns

Optimize DISTINCT queries for performance

Know when to use DISTINCT vs GROUP BY