Struct datafusion::physical_plan::udaf::AggregateUDF

pub struct AggregateUDF {
    pub name: String,
    pub signature: Signature,
    pub return_type: Arc<dyn Fn(&[DataType]) -> Result<Arc<DataType>, DataFusionError> + Sync + Send + 'static>,
    pub accumulator: Arc<dyn Fn(&DataType) -> Result<Box<dyn Accumulator + 'static, Global>, DataFusionError> + Sync + Send + 'static>,
    pub state_type: Arc<dyn Fn(&DataType) -> Result<Arc<Vec<DataType, Global>>, DataFusionError> + Sync + Send + 'static>,
}

Logical representation of a user-defined aggregate function (UDAF) A UDAF is different from a UDF in that it is stateful across batches.

Fields

name: String

name

signature: Signature

signature

return_type: Arc<dyn Fn(&[DataType]) -> Result<Arc<DataType>, DataFusionError> + Sync + Send + 'static>

Return type

accumulator: Arc<dyn Fn(&DataType) -> Result<Box<dyn Accumulator + 'static, Global>, DataFusionError> + Sync + Send + 'static>

actual implementation

state_type: Arc<dyn Fn(&DataType) -> Result<Arc<Vec<DataType, Global>>, DataFusionError> + Sync + Send + 'static>

the accumulator’s state’s description as a function of the return type

Implementations

impl AggregateUDF

pub fn new(
    name: &str,
    signature: &Signature,
    return_type: &Arc<dyn Fn(&[DataType]) -> Result<Arc<DataType>, DataFusionError> + Sync + Send + 'static>,
    accumulator: &Arc<dyn Fn(&DataType) -> Result<Box<dyn Accumulator + 'static, Global>, DataFusionError> + Sync + Send + 'static>,
    state_type: &Arc<dyn Fn(&DataType) -> Result<Arc<Vec<DataType, Global>>, DataFusionError> + Sync + Send + 'static>
) -> AggregateUDF

Create a new AggregateUDF

pub fn call(&self, args: Vec<Expr, Global>) -> Expr

creates a logical expression with a call of the UDAF This utility allows using the UDAF without requiring access to the registry.

Trait Implementations

impl Clone for AggregateUDF

fn clone(&self) -> AggregateUDF

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for AggregateUDF

fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>

Formats the value using the given formatter.

impl Hash for AggregateUDF

fn hash<H>(&self, state: &mut H)where
    H: Hasher,

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)where
    H: Hasher,
    Self: Sized,

Feeds a slice of this type into the given Hasher.

impl PartialEq<AggregateUDF> for AggregateUDF

fn eq(&self, other: &AggregateUDF) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Eq for AggregateUDF