Meaning of The hash of the query dictionary. (This is a 256-bit SHA3 hash of the query dict.)

Hello,

I've been searching for information on how to recreate the hash, and I'd like to understand the meaning of the statement: "The hash of the query dictionary. (This is a 256-bit SHA3 hash of the query dict.)" What does this mean?

It’s a data structure Clojure - Data Structures

Could you provide an example of how to accomplish this? Is it not achievable through SQL?