Re: reduce execution time of query

[Rick James]

Please use explicit JOIN (instead of "comma join").

Please use short aliases; long ones clutter the query and make it hard to read.

select  sum(rf.total_price) as m0
    from  category_groups as cg
    join  dim_products as dp on dp.product_category_group_sk = cg.product_category_group_sk
    join  revenue_facts as rf on rf.product_sk = dp.product.sk
    group by  cg.category_name ;

Check the result -- sometimes users are in for a surprise when using GROUP BY with JOIN; the sum may be many times as big as expected.

> I already have indexes on ... the columns in join.

Please provide SHOW CREATE TABLE for each table, so we can check engines, datatypes, etc.