OVER and PARTITION BY: a summary beside each row
Keep one order per row and attach its customer’s order total. Separate population filtering, partitioning and display order.
A window function attaches information to each input row without collapsing groups. PARTITION BY defines the rows sharing a calculation. With no ORDER BY inside OVER, this sum covers the entire filtered partition.
- OVER and PARTITION BY: a summary beside each row
- A window function attaches information to each input row without collapsing groups. PARTITION BY defines the rows sharing a calculation. With no ORDER BY inside OVER, this sum covers the entire filtered partition.