VARIANCE,VAR_POP,VARIANCE_POP

description

Syntax

VARIANCE(expr)

返回expr表达式的方差

example

MySQL > select variance(scan_rows)
from log_statis
group by datetime;
+-----------------------+
| variance(`scan_rows`) |
+-----------------------+
|    5.6183332881176211 |
+-----------------------+

MySQL > select var_pop(scan_rows)
from log_statis
group by datetime;
+----------------------+
| var_pop(`scan_rows`) |
+----------------------+
|   5.6230744719006163 |
+----------------------+

keyword

VARIANCE,VAR_POP,VARIANCE_POP,VAR,POP