Struct datafusion_physical_expr::window::BuiltInWindowExpr

pub struct BuiltInWindowExpr { /* private fields */ }

A window expr that takes the form of a built in window function

Implementations

impl BuiltInWindowExpr

pub fn new( expr: Arc<dyn BuiltInWindowFunctionExpr>, partition_by: &[Arc<dyn PhysicalExpr>], order_by: &[PhysicalSortExpr], window_frame: Arc<WindowFrame> ) -> Self

create a new built-in window function expression

pub fn get_built_in_func_expr(&self) -> &Arc<dyn BuiltInWindowFunctionExpr>

Get BuiltInWindowFunction expr of BuiltInWindowExpr

Trait Implementations

impl Debug for BuiltInWindowExpr

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

Formats the value using the given formatter.

impl WindowExpr for BuiltInWindowExpr

fn as_any(&self) -> &dyn Any

Return a reference to Any that can be used for downcasting

fn evaluate_stateful( &self, partition_batches: &PartitionBatches, window_agg_state: &mut PartitionWindowAggStates ) -> Result<()>

Evaluate the window function against the batch. This function facilitates stateful, bounded-memory implementations.

fn name(&self) -> &str

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

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

The field of the final result of this window function.

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

Expressions that are passed to the WindowAccumulator. Functions which take a single input argument, such as sum, return a single datafusion_expr::expr::Expr, others (e.g. cov) return many.

fn partition_by(&self) -> &[Arc<dyn PhysicalExpr>]

Expressions that’s from the window function’s partition by clause, empty if absent

fn order_by(&self) -> &[PhysicalSortExpr]

Expressions that’s from the window function’s order by clause, empty if absent

fn evaluate(&self, batch: &RecordBatch) -> Result<ArrayRef>

Evaluate the window function values against the batch

fn get_window_frame(&self) -> &Arc<WindowFrame>

Get the window frame of this WindowExpr.

fn get_reverse_expr(&self) -> Option<Arc<dyn WindowExpr>>

Get the reverse expression of this WindowExpr.

fn uses_bounded_memory(&self) -> bool

Return a flag indicating whether this WindowExpr can run with bounded memory.

fn evaluate_args(&self, batch: &RecordBatch) -> Result<Vec<ArrayRef>>

Evaluate the window function arguments against the batch and return array ref, normally the resulting Vec is a single element one.

fn evaluate_partition_points( &self, num_rows: usize, partition_columns: &[SortColumn] ) -> Result<Vec<Range<usize>>>

Evaluate the partition points given the sort columns; if the sort columns are empty then the result will be a single element Vec of the whole column rows.

fn order_by_columns(&self, batch: &RecordBatch) -> Result<Vec<SortColumn>>

Get order by columns, empty if absent

fn sort_columns(&self, batch: &RecordBatch) -> Result<Vec<SortColumn>>

Get sort columns that can be used for peer evaluation, empty if absent

fn get_values_orderbys( &self, record_batch: &RecordBatch ) -> Result<(Vec<ArrayRef>, Vec<ArrayRef>)>

Get values columns (argument of Window Function) and order by columns (columns of the ORDER BY expression) used in evaluators