Categories:

Aggregate Functions (Linear Regression) , Window Functions

# REGR_AVGY¶

Returns the average of the dependent variable for non-null pairs in a group, where x is the independent variable and y is the dependent variable.

## Syntax¶

Aggregate function

REGR_AVGY(y, x)


Window function

REGR_AVGY(y, x) OVER ( [ PARTITION BY <expr3> ] )


## Arguments¶

y

The dependent variable. This must be an expression that can be evaluated to a numeric type.

x

The independent variable. This must be an expression that can be evaluated to a numeric type.

expr3

This is the optional expression used to group rows into partitions.

Important

Note the order of the arguments; the dependent variable is first.

## Usage Notes¶

• DISTINCT is not supported for this function.

• In order for a row to be included in the average, BOTH the x and y values must be non-NULL.

• When used as a window function:

• This function does not support:

• ORDER BY sub-clause in the OVER() clause.

• Window frames.

## Examples¶

create or replace table aggr(k int, v decimal(10,2), v2 decimal(10, 2));
insert into aggr values(1, 10, null);
insert into aggr values(2, 10, 11), (2, 20, 22), (2, 25,null), (2, 30, 35);

select k, regr_avgy(v, v2) from aggr group by k;

---+------------------+
k | regr_avgy(v, v2) |
---+------------------+
1 | [NULL]           |
2 | 20               |
---+------------------+