Introduction: Unveiling Window Functions
Window functions are a powerful feature in PostgreSQL that can transform the way you analyze and extract insights from your data. Unlike traditional aggregate functions, window functions allow you to perform calculations across a set of table rows related to the current row. In this comprehensive guide, we’ll start with the basics of window functions and gradually dive into simple yet practical use cases.
Section 1: Understanding the OVER() Clause
The key to working with window functions is the `OVER()` clause. This clause defines the window or set of rows that the function will operate on. It allows you to specify the partitioning and ordering of rows within the window.
In this example, we’re calculating the average salary within each department using the `PARTITION BY` clause within the `OVER()` clause.
