IN vs Union All in SQL Server

One option for improving query performance is to rewrite the query in order to obtain a completely different execution plan. In this episode we look at how it's possible to rewrite queries with correlated subqueries into derived table syntax and examine what causes the difference in performance.

Subscribe and turn on notifications to never miss a weekly video: https://www.youtube.com/c/DataWithBert?sub_confirmation=1

Related blog post with example code:
https://bertwagner.com/2019/04/23/correlated-subqueries-vs-derived-tables/

Follow me on Twitter:
https://twitter.com/bertwagner

Видео IN vs Union All in SQL Server канала Bert Wagner