pub struct SlidingAggregateWindowExpr { /* private fields */ }
Expand description
A window expr that takes the form of an aggregate function that can be incrementally computed over sliding windows.
See comments on WindowExpr
for more details.
Implementations§
source§impl SlidingAggregateWindowExpr
impl SlidingAggregateWindowExpr
sourcepub fn new(
aggregate: Arc<dyn AggregateExpr>,
partition_by: &[Arc<dyn PhysicalExpr>],
order_by: &[PhysicalSortExpr],
window_frame: Arc<WindowFrame>
) -> Self
pub fn new( aggregate: Arc<dyn AggregateExpr>, partition_by: &[Arc<dyn PhysicalExpr>], order_by: &[PhysicalSortExpr], window_frame: Arc<WindowFrame> ) -> Self
Create a new (sliding) aggregate window function expression.
sourcepub fn get_aggregate_expr(&self) -> &Arc<dyn AggregateExpr>
pub fn get_aggregate_expr(&self) -> &Arc<dyn AggregateExpr>
Get the AggregateExpr of this object.
Trait Implementations§
source§impl Debug for SlidingAggregateWindowExpr
impl Debug for SlidingAggregateWindowExpr
source§impl WindowExpr for SlidingAggregateWindowExpr
impl WindowExpr for SlidingAggregateWindowExpr
Incrementally update window function using the fact that batch is pre-sorted given the sort columns and then per partition point.
Evaluates the peer group (e.g. SUM
or MAX
gives the same results
for peers) and concatenate the results.
source§fn name(&self) -> &str
fn name(&self) -> &str
Human readable name such as
"MIN(c2)"
or "RANK()"
. The default
implementation returns placeholder text.source§fn expressions(&self) -> Vec<Arc<dyn PhysicalExpr>>
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.source§fn evaluate(&self, batch: &RecordBatch) -> Result<ArrayRef>
fn evaluate(&self, batch: &RecordBatch) -> Result<ArrayRef>
Evaluate the window function values against the batch
source§fn evaluate_stateful(
&self,
partition_batches: &PartitionBatches,
window_agg_state: &mut PartitionWindowAggStates
) -> Result<()>
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.
source§fn partition_by(&self) -> &[Arc<dyn PhysicalExpr>]
fn partition_by(&self) -> &[Arc<dyn PhysicalExpr>]
Expressions that’s from the window function’s partition by clause, empty if absent
source§fn order_by(&self) -> &[PhysicalSortExpr]
fn order_by(&self) -> &[PhysicalSortExpr]
Expressions that’s from the window function’s order by clause, empty if absent
source§fn get_window_frame(&self) -> &Arc<WindowFrame>
fn get_window_frame(&self) -> &Arc<WindowFrame>
Get the window frame of this WindowExpr.
source§fn get_reverse_expr(&self) -> Option<Arc<dyn WindowExpr>>
fn get_reverse_expr(&self) -> Option<Arc<dyn WindowExpr>>
Get the reverse expression of this WindowExpr.
source§fn uses_bounded_memory(&self) -> bool
fn uses_bounded_memory(&self) -> bool
Return a flag indicating whether this WindowExpr can run with
bounded memory.
source§fn evaluate_args(&self, batch: &RecordBatch) -> Result<Vec<ArrayRef>>
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.source§fn order_by_columns(&self, batch: &RecordBatch) -> Result<Vec<SortColumn>>
fn order_by_columns(&self, batch: &RecordBatch) -> Result<Vec<SortColumn>>
Get order by columns, empty if absent
Auto Trait Implementations§
impl !RefUnwindSafe for SlidingAggregateWindowExpr
impl Send for SlidingAggregateWindowExpr
impl Sync for SlidingAggregateWindowExpr
impl Unpin for SlidingAggregateWindowExpr
impl !UnwindSafe for SlidingAggregateWindowExpr
Blanket Implementations§
source§impl<T> BorrowMut<T> for Twhere
T: ?Sized,
impl<T> BorrowMut<T> for Twhere T: ?Sized,
source§fn borrow_mut(&mut self) -> &mut T
fn borrow_mut(&mut self) -> &mut T
Mutably borrows from an owned value. Read more