var_samp,variance_samp
Description
Returns the sample variance of an expression. Since v2.5.10, this function can also be used as a window function.
Syntax
VAR_SAMP(expr)
Parameters
expr
: the expression. If it is a table column, it must evaluate to TINYINT, SMALLINT, INT, BIGINT, LARGEINT, FLOAT, DOUBLE, or DECIMAL.
Return value
Returns a DOUBLE value.
Examples
MySQL > select var_samp(scan_rows)
from log_statis
group by datetime;
+-----------------------+
| var_samp(`scan_rows`) |
+-----------------------+
| 5.6227132145741789 |
+-----------------------+
keyword
VAR_SAMP,VARIANCE_SAMP,VAR,SAMP,VARIANCE