Applies to: Databricks SQL Databricks Runtime
Returns the mean calculated from values of a group. This function is a synonym for avg aggregate function.
mean ( [ALL | DISTINCT] expr ) [FILTER ( WHERE cond ) ]
This function can also be invoked as a window function using the
expr: An expression that evaluates to a numeric.
cond: An optional boolean expression filtering the rows used for aggregation.
The result type is computed as for the arguments:
DECIMAL(p, s): The result type is a` DECIMAL(p + 4, s + 4)`. If the maximum precision for DECIMAL is reached, the increase in scale is limited to avoid loss of significant digits.
year-month interval: The result is an
INTERVAL YEAR TO MONTH.
day-time interval: The result is an
INTERVAL DAY TO SECOND.
In all other cases the result is a DOUBLE.
Nulls within the group are ignored. If a group is empty or consists only of nulls the result is NULL.
DISTINCT is specified the mean is computed after duplicates have been removed.
In Databricks Runtime, if spark.sql.ansi.enabled is
false, an overflow returns
NULL instead of an error.