Mega Code Archive
PERCENT_RANK
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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
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