What does SPJ stand for in MySQL parlance? MySQL has a lot of references to SPJ in MySQL including in official Oracle slides but I can't find what it actually stands for. I see it show up in a few blogs too.

I looked in the source and found nothing.

What does SPJ stand for?
Apparently it stands for "Select Project Join":


  What’s in a name?
  
  If some of this seems familiar but you don’t remember hearing the term
  “Adaptive Query Localization” before then you’re not going crazy –
  previous internal names were SPJ (Select Project Join) and Pushed-Down
  Joins. We just figured that Adaptive Query Localization was more
  descriptive.


Source: Dramatically Increased MySQL Cluster JOIN performance with Adaptive Query Localization