SQL SERVER! SARGability: the One Concept You Absolutely Must Understand!
Hi SQL SERVER Guys, Welcome back to this series about the most important concepts about performance! If you care about SQL Server performance, you cannot miss this post becuase there is one concept you absolutely must understand: SARGability . In a previous post I showed how dangerous some SQL queries can be for performance: The Most Dangerous SQL Server Query Today we look at one of the most important techniques to write faster queries: the SARGable way . What does SARGable mean? SARGable stands for Search ARGument ABLE . It means SQL Server can use an index efficiently to find rows. When a predicate is SARGable SQL Server can perform an: Index Seek (fast) When it is not SARGable SQL Server often performs an: Index Scan (slow) A classic NON-SARGable query SELECT * FROM Orders WHERE YEAR(OrderDate) = 2024; This query looks simple, but it hides a performance problem. Because the column is wrapped in the function YEAR() , SQL Serve...