Saturday, May 16, 2026

SQL 2025 master class LAB 15 Optimize Query

 

 Look at the query plan of the following query

Remove all underlying indexes and statistics from the database

Revisit the execution plan

Use the optimizer to optimize the underlying database

Consider the execution plan again

use adventureworks2025 

SELECT Sales.SalesOrderDetail.OrderQty, Sales.SalesOrderHeader.SalesOrderID, Sales.SalesOrderHeader.OrderDate,

Production.Product.Name, Production.ProductSubcategory.Name AS SubCat, Production.ProductCategory.Name AS Cat

FROM Production.ProductSubcategory LEFT OUTER JOIN

Production.ProductCategory ON Production.ProductSubcategory.ProductCategoryID = Production.ProductCategory.ProductCategoryID AND

Production.ProductSubcategory.ProductCategoryID = Production.ProductCategory.ProductCategoryID RIGHT OUTER JOIN

Production.Product ON Production.ProductSubcategory.ProductSubcategoryID = Production.Product.ProductSubcategoryID AND

Production.ProductSubcategory.ProductSubcategoryID = Production.Product.ProductSubcategoryID RIGHT OUTER JOIN

Sales.SalesOrderDetail ON Production.Product.ProductID = Sales.SalesOrderDetail.ProductID LEFT OUTER JOIN

Sales.SalesOrderHeader ON Sales.SalesOrderDetail.SalesOrderID = Sales.SalesOrderHeader.SalesOrderID

where color = 'red' and OrderQty = 18