Christina Leo is a Cloud Solution Architect at Microsoft specialising in the Data and AI Platform. Prior to joining Microsoft in 2016, she worked as an independent consultant focusing on T-SQL and BI development, as well as performance tuning.
Building Your T-SQL Tool Kit: Window Function Fundamentals
Sets are king when it comes to SQL Server, but sometimes you need to see data row by row. Window Functions help you get the best of both worlds. Learn when and where these functions can help you get what you need without compromising performance.
Have you pulled a script to identify duplicates from a blog post, but couldn’t quite get it to work, because you weren’t sure what that ROW_NUMBER() function was doing. Maybe you heard talk about creating running totals without using sub-queries, but you got frustrated when the groups weren’t totaling correctly. Or maybe, you’ve never even heard of Window Functions. All are good reasons to attend this demo-filled session which demystifies this versatile T-SQL tool. First, we’ll break apart the OVER clause, the key to understanding how window functions work. Then we’ll expand on each group of functions that can use the OVER clause: ranking, aggregate, and analytic functions. Finally, we’ll look at real scenarios where this tool works and talk about performance considerations. When you leave, you’ll have the fundamentals you need to fully develop your mastery of Window Functions.