Redshift's Window Functions Advanced use case - Sessionization

Jiří Mauritz Data Warehouse, Redshift, Window Functions

In the last post about the Window Functions, we introduced an advanced use case, in which the window functions help to make the query more readable, simple and efficient. The problem was to find free call intervals for each customer, which are created as customers tops-up their credit for at least €20 and get free calls for the next 28 ...