Was curious myself so asked chatgpt and this what I got:
Nested aggregates in databases are useful when you want to perform calculations or summaries on groups of data within larger groups. For example, imagine you have a database of sales transactions with products and categories. You could use nested aggregates to find the total sales for each category and then calculate the average sales per category. It saves effort by allowing you to perform calculations at different levels of granularity in a single query.
Nested aggregates in databases are useful when you want to perform calculations or summaries on groups of data within larger groups. For example, imagine you have a database of sales transactions with products and categories. You could use nested aggregates to find the total sales for each category and then calculate the average sales per category. It saves effort by allowing you to perform calculations at different levels of granularity in a single query.