Hello, >From a table x(c1) containing 30 lines with integer values (column c1) from 1 >to 30 :
SELECT percentile_cont(1./3) WITHIN GROUP (ORDER BY c1) FROM x ; percentile_cont ------------------ 10.6666666666667 (1 ligne) SELECT percentile_cont(2./3) WITHIN GROUP (ORDER BY c1) FROM x ; percentile_cont ------------------ 20.3333333333333 (1 ligne) If ordering, the first 10 lines (c1 from 1 to 10) have ntile(3) OVER(ORDER BY c1) = 1, the 10 following lines (c1 from 11 to 20) have ntile(3) OVER(ORDER BY c1) = 2, the last 10 lines (c1 from 21 to 30) have ntile(3) OVER(ORDER BY c1) = 3. So, I though it should be : percentile_cont(1./3) = 10.5 (the arithmetic average between 10 et 11) and not 10.6666666666667 percentile_cont(2./3) = 20.5 (the arithmetic average between 20 et 21) and not 20.3333333333333 Thank in advance for explanation ----- Météo-France ----- PALAYRET JACQUES DCSC/MBD jacques.palay...@meteo.fr Fixe : +33 561078319
