SQLBits 2018

The stuff about Joins they didnt teach you in school

Logical v Physical, Semi Joins, Lookup Joins, Redundant Joins - there is so much more to joins than you may have considered, and yet they are so fundamental to almost every query you ever write.
Joins are a thing you learn on Day 1 of T-SQL 101. But they are so much more involved than what you learned then. Logical v physical, Semi Joins, Lookup Joins, Redundant Joins, not to mention those times when you thought you specified one kind of join and the execution plan says it's doing something else.

Luckily, it's not magic - it's all very straightforward once you understand the different types of joins and how they work. This session will cover the different types of logical and physical joins - and even look at joins that don't exist at all.