Ich bin mir nicht ganz sicher, wie das zu deuten ist (aus meinem geposteten Link):
Zitat:
BETWEEN clause Use the BETWEEN clause to define the first and last row of the window, using the current row as a reference point. First and last rows are expressed in terms of the number of rows preceding and following the current row, respectively. For example, BETWEEN 3 PRECEDING AND 5 FOLLOWING sets the window to start with the third row preceding the current row, and end with the fifth row following the current row.