|Oracle® Database SQL Reference
10g Release 2 (10.2)
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See Also:"Analytic Functions" for information on syntax, semantics, and restrictions, including valid forms of
NTILE is an analytic function. It divides an ordered data set into a number of buckets indicated by
expr and assigns the appropriate bucket number to each row. The buckets are numbered 1 through
expr value must resolve to a positive constant for each partition. Oracle Database expects an integer, and if
expr is a noninteger constant, then Oracle truncates the value to an integer. The return value is
The number of rows in the buckets can differ by at most 1. The remainder values (the remainder of number of rows divided by buckets) are distributed one for each bucket, starting with bucket 1.
expr is greater than the number of rows, then a number of buckets equal to the number of rows will be filled, and the remaining buckets will be empty.
You cannot use
NTILE or any other analytic function for
expr. That is, you cannot nest analytic functions, but you can use other built-in function expressions for
See Also:"About SQL Expressions" for information on valid forms of
exprand Table 2-10, "Implicit Type Conversion Matrix" for more information on implicit conversion
The following example divides into 4 buckets the values in the
salary column of the
oe.employees table from Department 100. The
salary column has 6 values in this department, so the two extra values (the remainder of 6 / 4) are allocated to buckets 1 and 2, which therefore have one more value than buckets 3 or 4.
SELECT last_name, salary, NTILE(4) OVER (ORDER BY salary DESC) AS quartile FROM employees WHERE department_id = 100; LAST_NAME SALARY QUARTILE ------------------------- ---------- ---------- Greenberg 12000 1 Faviet 9000 1 Chen 8200 2 Urman 7800 2 Sciarra 7700 3 Popp 6900 4