GBase 8a QUALIFY Clause: Filtering Window Functions the Smart Way

When you use window functions in SQL, you can't filter their results directly in a WHERE or HAVING clause — that's a well‑known limitation across many databases. GBase 8a, the China‑domestically developed MPP database from GBASE, solves this elegantly with the QUALIFY clause. Let's break down how it works, what it can do, and where you need to be careful. Sample Table DROP TABLE IF EXISTS emp ; CREATE TABLE emp ( id INT , name VARCHAR ( 30 ) NOT NULL , gender VARCHAR ( 30 ) NOT NULL , sex INT NO