In my daily use of SQL queries, aggregate functions are used to perform calculations on a set of values, returning a single value. Common examples include SUM, AVG, COUNT, MIN, and MAX.

To support aggregate window functions, the following two problems need to be addressed: How to make existing aggregate functions work as window function; How to handle duplicate sort key (field values ...

Using an aggregate function, you can create a summary for all the values in a table. For example, you can create a query such as the following to display the total price for all books in the titles ...