VAR_SAMP function calculates the sample variance.
The general format for this function is:
VAR_SAMP(expr)
SQL> SQL>-- w ww . ja v a 2 s .c o m SQL> SELECT VAR_SAMP(y) FROM my_table; VAR_SAMP(Y) ----------- 75434.62 SQL>
Given the following table.
SQL> SQL> drop table my_table; Table dropped.-- w w w .ja v a 2s .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>