3. Key Lookups and Cardinality Estimation (41 min)
Why does one query get wildly different execution plans? Learn how statistics influence your query plans, discover how to see your own statistics, and understand how stats help build memory grants.
We finished part 3 with two similar-looking queries that produce very different behavior: one does a seek, and the other does a scan. Now you’ll learn why, plus add yet another index to make this query go faster, and then discuss the drawbacks of too many indexes.
7 Comments. Leave new
Interesting video man. As always, I appreciate it!
Good information on INDEX STATISTICS. I like DBCC SHOW_STATISTICS allowing me to determine the actual sample size.
*cough* Oracle™ does *cough*. I laughed a lot.
Thanks for the video.
FYI, when selecting
mark as completebutton, it redirects to https://www.brentozar.com/training/think-like-sql-server-engine/4-sargability-10-min/ which seems to be a dead linkthank you.
Sorry about that! Fixed.
“Point to the screen where the bad man touched you.”? You made me snort coffee. :p
Thanks for the practical explanation of how the dumb guy thinks.
Hahaha, glad you liked it!