| 16. 6. 1. PERCENT_RANK |
|
|
PERCENT_RANK will compute the cumulative fraction of the ranking that exists for a particular ranking value. |
This calculation and the one for CUME_DIST are like the values one would see in a histogram. |
PERCENT_RANK is set to compute so that the first row is zero, and the other values in this column are computed based on the formula: |
Percent_rank (PR) = (Rank-1)/(Number of rows-1) |
The CUME_RANK function calculates the cumulative distribution in a group of values. |
If we have only one group, so the formula works like this: |
Cumulative Distribution = the highest rank for that row (cr)/number of rows (nr) |
Quote from: |
Advanced SQL Functions in Oracle 10g (Wordware Applications Library) |
(Paperback) |
by Richard Earp (Author) |
# Paperback: 350 pages |
# Publisher: Wordware Publishing, Inc. (January 25, 2006) |
# Language: English |
# ISBN-10: 1598220217 |
# ISBN-13: 978-1598220216 |