STDDEV_POP function computes the population standard deviation and gives the square root of the population variance.
The general format for this function is:
STDDEV_POP(expr) [OVER(analytic_clause)]
SQL> SQL>-- w w w. j a v a 2s. c o m SQL> SELECT STDDEV_POP(y) FROM my_table; STDDEV_POP(Y) ------------- 00267.33 SQL>
Given the following table.
SQL> SQL> drop table my_table; Table dropped.-- w w w . j a v a2 s . c o m SQL> create table my_table( 2 x NUMBER(4) primary key, 3 y NUMBER(4) not null); SQL> SQL> insert into my_table values(1,2); SQL> insert into my_table values(2,4); SQL> insert into my_table values(3,6); SQL> insert into my_table values(4,9); SQL> insert into my_table values(5,13); SQL> insert into my_table values(6,16); SQL> insert into my_table values(7,20); SQL> insert into my_table values(8,27); SQL> insert into my_table values(9,32); SQL> insert into my_table values(10,47); SQL> insert into my_table values(11,53); SQL> insert into my_table values(12,60); SQL> insert into my_table values(13,76); SQL> insert into my_table values(14,100); SQL> insert into my_table values(15,130); SQL> insert into my_table values(16,189); SQL> insert into my_table values(17,300); SQL> insert into my_table values(18,789); SQL> insert into my_table values(19,1000); SQL>