What does the project of Operator types mean

And there are two PROJECT,why…

Hi @flaming-archer,

The duplicate PROJECT in that list is a typo. Thank you for pointing it out. We’ve corrected it.

The PROJECT operator implements the SELECT that you write into your queries. So if you have:

SELECT name, date, id FROM your-dataset

… You’ll see an operator like this in the plan:

Project(name=[$0], date=[$1], id=[$2) ...

You can find more information about the relational algebra operator this is adapted from here.