AVG

Calculates the average of an expression.

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Syntax

AVG(<value>)

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Parameters

Valid values for the expression include column names or functions that return a column name (or columns) that contain numeric values.

The AVG() aggregation function ignores rows with NULL values. For example, an AVG from 3 rows containing 1, 2, and NULL returns 1.5 because the NULL row is not counted. To calculate an average that includes NULL, use SUM(COLUMN)/COUNT(*).

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Return Types

• NUMERIC if the input is type INTEGER, BIGINT or NUMERIC
• DOUBLE PRECISION if the input is type REAL or DOUBLE PRECISION

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Precision and Determinism

Applying AVG to REAL and DOUBLE PRECISION is subject to floating point arithmetic accuracy limitations and its resulting error. This error may add up when aggregating multiple values.

The order of operations while computing the aggregate is non-deterministic. This can lead to varying total floating point error when running a query multiple times. If this is not acceptable for your use-case, aggregate on NUMERIC data instead.

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Example

The example below uses the following table LevelPoints. This table includes the maximum points a player can score at each level of the game:

Use the query below to find the average of the maxpoints value.

SELECT 
    AVG(maxpoints) AS AverageMaxPoints 
FROM levels;

Returns: