Optimizing Ordered Results Retrieval in MySQL with EXPLAIN

Analyze Query with ORDER BY and LIMIT using EXPLAIN

Write a MySQL query that uses EXPLAIN to analyze a query retrieving the top 5 highest order amounts from the Orders table.

Solution:

-- Use EXPLAIN to analyze the performance of an ORDER BY query with a LIMIT clause.
EXPLAIN SELECT * FROM Orders
ORDER BY TotalAmount DESC
LIMIT 5;

Explanation:

• Purpose of the Query:
• To examine how MySQL executes a query that sorts data and limits the output.
• Useful for optimizing queries that involve ordering large datasets.
• Key Components:
• ORDER BY TotalAmount DESC : Sorts the records in descending order by order amount.
• LIMIT 5 : Restricts the output to the top 5 records.
• Real-World Application:
• Common in dashboards or reports highlighting top-performing orders.

Notes:

• An index on TotalAmount can speed up sorting operations.
• Use EXPLAIN output to refine index strategy for ordered queries.

For more Practice: Solve these Related Problems:

• Write a MySQL query that uses EXPLAIN to analyze a query retrieving the top 10 highest revenue products from the Sales table.
• Write a MySQL query that uses EXPLAIN to analyze a query retrieving the top 5 most expensive projects from the Projects table.
• Write a MySQL query that uses EXPLAIN to analyze a query retrieving the top 7 most active customers from the Customers table.
• Write a MySQL query that uses EXPLAIN to analyze a query retrieving the top 3 most recent orders from the Orders table.

Go to:

• MySQL Query Optimization Exercises Home. ↩
• MySQL Exercises Home ↩

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