• Optimizing JOIN conditions
• Filtering records early in the query
• Optimizing the query’s order of operations
• Adding redundant subqueries

The correct answer is: Adding redundant subqueries

Explanation: Adding redundant subqueries is NOT a method of optimizing your AMC SQL.

Redundant subqueries can increase query complexity and slow down performance. Best practices encourage filtering data early, using efficient join strategies, leveraging UNION ALL instead of unnecessary joins, and eliminating unnecessary subqueries or nested structures to make queries more efficient.

Reference content: From Amazon’s official documentation – Optimize AMC SQL queries

“Best practice summary:

• Filter data early and properly
• Leverage UNION ALL instead of JOIN when possible
• Optimize join order
• Avoid logical errors and hidden costs (such as redundant subqueries) …”

General best practices – SQL optimization overview:

“Eliminate redundant subqueries”