In May, I presented two talks – one called “Are you getting the
best out of your indexes?” and “Optimizing Queries Using
EXPLAIN”. I now have slides and video for both of them.
The first talk about indexing should probably be titled “Why is
MySQL doing this?!!?!!?” It gives insight into why the MySQL
optimizer chooses indexes that you do not expect; especially when
it does not use an index you expect it to.
The talk has something for everyone – for beginners it explains
B-trees and how they work, and for the more seasoned DBA it
explains concepts like average value group size, and how the
optimizer uses those concepts applied to metadata to make
Slides are at http://technocation.org/files/doc/2017_05_MySQLindexes.pdf.[Read more]
Click the slide image below to go to the video at …