The query is executing very slowly, is there any way to improve it any further?

Question

I have the following query, and because of a lot of SUM function calls, my query is running too slow. I have a lot of records in my database and I would like to get

Answer 1

Just use computed colums

Example

ALTER TABLE tb1 ADD [Current - Last 30 Days Col1] AS (CASE WHEN a.DateCol >= DATEADD(MONTH,-1,GETDATE()) THEN a.col1 ELSE 0 END) PERSISTED;

Specify Computed Columns in a Table