Struct datafusion::physical_expr::expressions::WindowShift

pub struct WindowShift { /* private fields */ }

window shift expression

Implementations

impl WindowShift

pub fn get_shift_offset(&self) -> i64

Get shift_offset of window shift expression

Trait Implementations

impl BuiltInWindowFunctionExpr for WindowShift

fn as_any(&self) -> &(dyn Any + 'static)

Return a reference to Any that can be used for downcasting

fn field(&self) -> Result<Field, DataFusionError>

The field of the final result of evaluating this window function.

fn expressions(&self) -> Vec<Arc<dyn PhysicalExpr>, Global>

Expressions that are passed to the PartitionEvaluator.

fn name(&self) -> &str

Human readable name such as "MIN(c2)" or "RANK()". The default implementation returns placeholder text.

fn create_evaluator( &self ) -> Result<Box<dyn PartitionEvaluator, Global>, DataFusionError>

Create a PartitionEvaluator for evaluating the function on a particular partition.

fn reverse_expr(&self) -> Option<Arc<dyn BuiltInWindowFunctionExpr>>

Construct a new BuiltInWindowFunctionExpr that produces the same result as this function on a window with reverse order. The return value of this function is used by the DataFusion optimizer to avoid re-sorting the data when possible.

fn evaluate_args( &self, batch: &RecordBatch ) -> Result<Vec<Arc<dyn Array>, Global>, DataFusionError>

Evaluate window function’s arguments against the input window batch and return an ArrayRef.

fn add_equal_orderings(&self, _builder: &mut OrderingEquivalenceBuilder)

Adds any equivalent orderings generated by this expression to builder.

impl Debug for WindowShift

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

Formats the value using the given formatter.