Checks whether the mean (average) of all the values in a column matches a given expression.
Syntax
Mean<COL_NAME><EXPRESSION>
COL_NAME – The name of the column that you want to evaluate the data quality rule against.
Supported column types: Byte, Decimal, Double, Float, Integer, Long, Short
EXPRESSION – An expression to run against the rule type response in order to produce a Boolean value. For more information, see Expressions.
Example: Average value
The following example rule checks whether the average of all of the values in a column exceeds a threshold.
Mean "Star_Rating" > 3
Mean "Salary" < 6200 where "Customer_ID < 10"Sample dynamic rules
Mean "colA" > avg(last(10)) + std(last(2))Mean "colA" between min(last(5)) - 1 and max(last(5)) + 1
Null behavior
The Mean rule will ignore rows with NULL values in the calculation of the mean. For example:
+---+-----------+
|id |units |
+---+-----------+
|100|0 |
|101|null |
|102|20 |
|103|null |
|104|40 |
+---+-----------+
The mean of column units will be (0 + 20 + 40) / 3 = 20. Rows 101 and 103 are not considered in this calculation.
