SQL Query Optimization: Combining Multiple Joins for Improved Performance

[mark01]

I'm working on an SQL query for a complex reporting system that involves multiple tables and joins. However, the query's performance is not meeting my expectations, and I suspect that the way I've structured my joins might be inefficient.


Here's a simplified version of my query:

SELECT
    orders.order_id,
    customers.customer_name,
    products.product_name,
    order_details.quantity,
    order_details.unit_price
FROM
    orders
JOIN
    customers ON orders.customer_id = customers.customer_id
JOIN
    order_details ON orders.order_id = order_details.order_id
JOIN
    products ON order_details.product_id = products.product_id
WHERE
    orders.order_date BETWEEN '2023-01-01' AND '2023-12-31';

While this query returns the correct results, it's taking a significant amount of time to execute, especially when dealing with a large dataset.


I'd like to optimize this query for better performance. Could someone review my SQL code and suggest improvements or alternative approaches to achieve the same result more efficiently? Additionally, are there any indexing strategies or database design considerations that might help enhance the query's speed? Any insights or code optimizations would be greatly appreciated. Thank you!

[Aussiebear]

Have a look here to see if this can improve your code. https://blog.devart.com/how-to-optimize-sql-query.html. In particular look at the section where it recommends keeping the number of joins to a minimum by using Inner Join

[arnelgp]

you should also try to create index on the Join fields and on the Criteria field.

[peevishscarf]

you should also try to create index on the Join fields and on the Criteria field.connections

How to create index on Join field and on Criteria field?

[Aussiebear]

try here for a start https://www.mssqltips.com/sqlservert...s-are-indexed/

[noah101]

you should also try to create index on the Join fields and on the Criteria field. immaculate grid

Thanks for sharing your expertise on indexing. Creating an index on the Join fields and on the Criteria field is a good suggestion to improve query performance.

[jdelano]

You can use this tool to see exactly where SQL Server uses the most time running the query Analyze an Actual Execution Plan - SQL Server | Microsoft Learn