Re: May I please know how the over iterator is being used here?

[rocuinneagain]

https://code.kx.com/q/ref/accumulators/#ternary-values

You can use a sample to see how it progresses:

 

({-1 .Q.s1 `x`y`z!(x;y;z);x+y+z}/)[0;1 2 3;4 5 6] 
`x`y`z!0 1 4 
`x`y`z!5 2 5 
`x`y`z!12 3 6 21

 

And on the ssr example:

 

({-1 .Q.s1 `x`y`z!(x;y;z);ssr[x;y;z]}/)["results_%div_%dept.csv"; ("%div";"%dept"); ("banking";"m&a")] 
`x`y`z!("results_%div_%dept.csv";"%div";"banking") 
`x`y`z!("results_banking_%dept.csv";"%dept";"m&a") 
"results_banking_m&a.csv"