MariaDB ColumnStore 1.1 introduces the Distributed User Defined Aggregate Functions (UDAF) C++ API. MariaDB Server has supported UDAF (a C API) for a while, but now we have extended it to the ColumnStore Engine. This new feature allows anyone to create aggregate functions of arbitrary complexity for distributed execution in the ColumnStore Engine. These functions can also be used as Analytic (Window) functions just like any built in aggregate. You should have a working understanding of C++ to use this API.