Expert T-SQL Window Functions in SQL Server 2019: The Hidden Secret to Fast Analytic and Reporting Queries

© Kathi Kellenberger, Clayton Groom, and Ed Pollack 2019

K. Kellenberger et al.Expert T-SQL Window Functions in SQL Server 2019https://doi.org/10.1007/978-1-4842-5197-3_9

9. Hitting a Home Run with Gaps, Islands, and Streaks

Kathi Kellenberger¹ , Clayton Groom² and Ed Pollack³

(1)

Edwardsville, IL, USA

(2)

Smithton, IL, USA

(3)

Albany, NY, USA

 

Within any set of data, we may examine how that data groups together. This can allow us to identify missing rows, find unusual patterns, or develop advanced analytical techniques. At its simplest, being able to locate gaps and islands will tell us about missing data values. As we delve deeper, it will allow us to identify streaks, droughts, or anomalous events worthy of further investigation.

At the core of this ...