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?

  • 1
    Don't know the answer, but in the header here: clusterdb.com/mysql-cluster/… it appears to mean push down join. What the S has to do with it is a mystery though :-)
    – Lennart
    Apr 14, 2018 at 6:47
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    Another mention is: johanandersson.blogspot.se/2010/04/… "SPJ (preview, not production ready) is a new feature allowing some types of JOINs to be pushed down and executed inside the data nodes! This allows for, in many cases, much faster JOIN execution."
    – Lennart
    Apr 14, 2018 at 6:52

1 Answer 1


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

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