Trait datafusion::execution::FunctionRegistry

pub trait FunctionRegistry {
    // Required methods
    fn udfs(&self) -> HashSet<String>;
    fn udf(&self, name: &str) -> Result<Arc<ScalarUDF>, DataFusionError>;
    fn udaf(&self, name: &str) -> Result<Arc<AggregateUDF>, DataFusionError>;
    fn udwf(&self, name: &str) -> Result<Arc<WindowUDF>, DataFusionError>;

    // Provided methods
    fn register_udf(
        &mut self,
        _udf: Arc<ScalarUDF>
    ) -> Result<Option<Arc<ScalarUDF>>, DataFusionError> { ... }
    fn register_udaf(
        &mut self,
        _udaf: Arc<AggregateUDF>
    ) -> Result<Option<Arc<AggregateUDF>>, DataFusionError> { ... }
    fn register_udwf(
        &mut self,
        _udaf: Arc<WindowUDF>
    ) -> Result<Option<Arc<WindowUDF>>, DataFusionError> { ... }
}

A registry knows how to build logical expressions out of user-defined function’ names

Required Methods

fn udfs(&self) -> HashSet<String>

Set of all available udfs.

fn udf(&self, name: &str) -> Result<Arc<ScalarUDF>, DataFusionError>

Returns a reference to the user defined scalar function (udf) named name.

fn udaf(&self, name: &str) -> Result<Arc<AggregateUDF>, DataFusionError>

Returns a reference to the user defined aggregate function (udaf) named name.

fn udwf(&self, name: &str) -> Result<Arc<WindowUDF>, DataFusionError>

Returns a reference to the user defined window function (udwf) named name.

Provided Methods

fn register_udf( &mut self, _udf: Arc<ScalarUDF> ) -> Result<Option<Arc<ScalarUDF>>, DataFusionError>

Registers a new ScalarUDF, returning any previously registered implementation.

Returns an error (the default) if the function can not be registered, for example if the registry is read only.

fn register_udaf( &mut self, _udaf: Arc<AggregateUDF> ) -> Result<Option<Arc<AggregateUDF>>, DataFusionError>

Registers a new AggregateUDF, returning any previously registered implementation.

Returns an error (the default) if the function can not be registered, for example if the registry is read only.

fn register_udwf( &mut self, _udaf: Arc<WindowUDF> ) -> Result<Option<Arc<WindowUDF>>, DataFusionError>

Registers a new WindowUDF, returning any previously registered implementation.

Returns an error (the default) if the function can not be registered, for example if the registry is read only.

Implementors

impl FunctionRegistry for SessionContext

impl FunctionRegistry for SessionState

impl FunctionRegistry for MemoryFunctionRegistry

impl FunctionRegistry for TaskContext