Custom Execution Plan

Here is an example in C++ of creating a custom execution plan with a hard-coded engine and knobs. Refer to the corresponding C++ sample in samples/cpp/misc/custom_plan.cpp.

Get the Engine Count

inline error_t
get_engine_count(int64_t &count);

Parameters

• count: number of engines [out parameter]

Return Value

• An error_t object indicating the success or failure of the function.

Get the Knobs Supported by an Engine

inline error_t
get_knobs_for_engine(int64_t const engine, std::vector<Knob> &);

Parameters

• engine: engine index
• knobs: list of knobs [out parameter]

Return Value

• An error_t object indicating the success or failure of the function.

Create Plan with a Particular Engine and Knobs

error_t
create_execution_plan(int64_t const engine_id, std::unordered_map<KnobType_t, int64_t> const &knobs);

Parameters

• engine_id: engine index
• knobs: knobs

Return Value

• An error_t object indicating the success or failure of the function.