The talk has the same name as this MySQL University session but the slides have been thoroughly re-worked, and also there is new content:
- More detailed explanation of subquery handling in 4.1/5.x
- More reliable/justified benchmark numbers
- Observations about subquery demographics
- An attempt at comparative analysis of how MySQL’s subquery strategies compare to PostgreSQL’s
- And a slide #28 that explains why we’re looking at PostgreSQL all the time
Have a nice viewing. And, if you get subqueries that should be fast but aren’t, we’re now actively looking at every subquery performance bug we get and will appreciate any input.