Alright! It's time to review what we've learned in this part:

• You can define a window frame within OVER(...). The syntax is: [ROWS|RANGE] <window frame definition>.
• ROWS always treats rows individually (like the ROW_NUMBER() function), RANGE also adds rows which share the same value in the column we order by (like the RANK() function).
• <window frame definition> is defined with BETWEEN <lower bound> AND <upper bound>, where the bounds may be defined with:
  • UNBOUNDED PRECEDING,
  • n PRECEDING (ROWS only),
  • CURRENT ROW,
  • n FOLLOWING (ROWS only),
  • UNBOUNDED FOLLOWING

So, are you ready for a short quiz?