Can we use window function with GROUP BY?

What is the difference between window functions and GROUP BY?

In short and very simplified: window functions retain result row, group by squashes them. If the information you need relates to aggregation you need group by , if the information relates to particular row you need window function.

Why is GROUP BY used in aggregate window functions?

By using the GROUP BY clause, you can calculate an aggregate value for several groups in one query. By using the aggregate function AVG() and GROUP BY , we get results that are grouped by date and city.

Is window function faster than GROUP BY?

The execution plan for the windowed function is clearly inferior to the execution plan for the group by (the whole group by execution plan is included in the top right of the windowed function execution plan). SQL in general is better optimized for group by than using an over clause, however each has their uses.

WHERE can be used with window functions?

Window functions precede ORDER BY. Drill processes window functions after the WHERE, GROUP BY, and HAVING clauses. Including the OVER() clause after an aggregate set function turns the function into an aggregate window function. You can use window functions to aggregate over any number of rows in the window frame.