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Expert T-SQL Window Functions in SQL Server 2019

The Hidden Secret to Fast Analytic and Reporting Queries

  • Kathi Kellenberger
  • Clayton Groom
  • Ed Pollack
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  • 3.6k Downloads

Table of contents

  1. Front Matter
    Pages i-xviii
  2. Kathi Kellenberger, Clayton Groom, Ed Pollack
    Pages 1-19
  3. Kathi Kellenberger, Clayton Groom, Ed Pollack
    Pages 21-41
  4. Kathi Kellenberger, Clayton Groom, Ed Pollack
    Pages 43-60
  5. Kathi Kellenberger, Clayton Groom, Ed Pollack
    Pages 61-74
  6. Kathi Kellenberger, Clayton Groom, Ed Pollack
    Pages 75-85
  7. Kathi Kellenberger, Clayton Groom, Ed Pollack
    Pages 87-98
  8. Kathi Kellenberger, Clayton Groom, Ed Pollack
    Pages 99-111
  9. Kathi Kellenberger, Clayton Groom, Ed Pollack
    Pages 113-139
  10. Kathi Kellenberger, Clayton Groom, Ed Pollack
    Pages 141-173
  11. Kathi Kellenberger, Clayton Groom, Ed Pollack
    Pages 175-193
  12. Kathi Kellenberger, Clayton Groom, Ed Pollack
    Pages 195-208
  13. Back Matter
    Pages 209-213

About this book

Introduction

Become an expert who can use window functions to solve T-SQL query problems. Replace slow cursors and self-joins with queries that are easy to write and perform better. This new edition provides expanded examples, including a chapter from the world of sports, and covers the latest performance enhancements through SQL Server 2019. 

Window functions are useful in analytics and business intelligence reporting. They came into full blossom with SQL Server 2012, yet they are not as well known and used as often as they ought to be. This group of functions is one of the most notable developments in SQL, and this book shows how every developer and DBA can benefit from their expressive power in solving day-to-day business problems. Once you begin using window functions, such as ROW_NUMBER and LAG, you will discover many ways to use them. You will approach SQL Server queries in a different way, thinking about sets of data instead of individual rows. Your queries will run faster, be easier to write, and easier to deconstruct, maintain, and enhance in the future.

Just knowing and using these functions is not enough. You also need to understand how to tune the queries. Expert T-SQL Window Functions in SQL Server clearly explains how to get the best performance. The book also covers the rare cases when older techniques are the best bet.

You will:
  • Solve complex query problems without cumbersome self-joins that run slowly and are difficult to read
  • Create sliding windows in a result set for computing such as running totals and moving averages
  • Return aggregate and detail data simultaneously from the same SELECT statement
  • Compute lag and lead and other values that access data from multiple rows in a result set
  • Understand the OVER clause syntax and how to control the window
  • Avoid framing errors that can lead to unexpected results

Keywords

Analytic functions Business intelligence ranking functions ROW_NUMBER RANK LAG and LEAD FIRST_VALUE LAST_VALUE Aggregate functions Running totals Moving averages SQL

Authors and affiliations

  • Kathi Kellenberger
    • 1
  • Clayton Groom
    • 2
  • Ed Pollack
    • 3
  1. 1.EdwardsvilleUSA
  2. 2.SmithtonUSA
  3. 3.AlbanyUSA

Bibliographic information