NTILE « Analytical Functions « Oracle PL/SQL Tutorial

16.18.1.NTILE groups data by sort order into a variable number of percentile groupings
16.18.2.Get a clearer picture of the NTILE function
16.18.3.NTILE function works from row order after a ranking takes place
16.18.4.Nulls with the NTILE function
16.18.5.NTile with NULLS LAST
16.18.6.NTILE with NULLS FIRST (the default)
16.18.7.Using the NTILE() Function