# Aggregate functions
<a name="sql-functions-aggregated"></a>

 Aggregate functions are database operations that perform calculations across multiple rows of data to produce a single summarized result. These functions analyze data sets to return computed values like sums, averages, counts, or other statistical measures. 


|  **Function**  |  **Signature**  |  **Description**  | 
| --- | --- | --- | 
|  `AVG`  |  AVG (expression)  |  Returns the average of a numerical expression.  | 
|  `COUNT`  |  COUNT (expression)  |  Returns the number of rows that match the given criteria.  | 
|  `MAX`  |  MAX (expression)  |  Returns the largest value of the selected expressions.  | 
|  `MIN`  |  MIN (expression)  |  Returns the smallest value of the selected expressions.  | 
|  `SUM`  |  SUM (expression)  |  Returns the sum of a numerical expression.  | 
|  `STDDEV`  |  STDDEV (expression)  |  Returns the sample standard deviation.  | 
|  `GROUP BY`  |  GROUP BY expression  |  Returns a row created by the grouping columns.  | 
|  `HAVING`  |  HAVING boolean-expression  |  Returns group rows filtered by `GROUP BY` clause.  | 

Examples of all functions:


|  **Function**  |  **Example**  | 
| --- | --- | 
|  AVG  |  <pre>SELECT d.asset_id, d.property_id, AVG(d.int_value) FROM raw_time_series AS d</pre>  | 
|  COUNT  |  <pre>SELECT COUNT(d.int_value) FROM raw_time_series AS d</pre>  | 
|  MAX  |  <pre>SELECT MAX(d.int_value) FROM raw_time_series AS d</pre>  | 
|  MIN  |  <pre>SELECT MIN(d.int_value) FROM raw_time_series AS d</pre>  | 
|  SUM  |  <pre>SELECT SUM(d.int_value) FROM raw_time_series AS d</pre>  | 
|  STDDEV  |  <pre>SELECT STDDEV(d.int_value) FROM raw_time_series AS d</pre>  | 
|  [\[See the AWS documentation website for more details\]](http://docs.aws.amazon.com/iot-sitewise/latest/userguide/sql-functions-aggregated.html)  |  <pre>SELECT MAX(d.int_value) AS max_int_value, d.asset_id <br />FROM raw_time_series AS d <br />GROUP BY d.asset_id <br />HAVING MAX(d.int_value) > 5                      <br /></pre>  |