Window Functions for Data Analysis with Postgres
(crunchydata.com)
SQL makes sense when it's working on a single row, or even when it's aggregating across multiple rows. But what happens when you want to compare between rows of something you've already calculated? Or make groups of data and query those? Enter window functions.
SQL makes sense when it's working on a single row, or even when it's aggregating across multiple rows. But what happens when you want to compare between rows of something you've already calculated? Or make groups of data and query those? Enter window functions.