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# Aggregate functions

Aggregate functions work in the [normal](http://www.sql-tutorial.com/sql-aggregate-functions-sql-tutorial) way as expected by database experts.

ClickHouse also supports:

- [Parametric aggregate functions](parametric_functions.md#aggregate_functions_parametric), which accept other parameters in addition to columns.
- [Combinators](combinators.md#aggregate_functions_combinators), which change the behavior of aggregate functions.

