Struct datafusion::physical_plan::udaf::AggregateFunctionExpr
source · pub struct AggregateFunctionExpr { /* private fields */ }
Expand description
Physical aggregate expression of a UDAF.
Implementations§
source§impl AggregateFunctionExpr
impl AggregateFunctionExpr
sourcepub fn fun(&self) -> &AggregateUDF
pub fn fun(&self) -> &AggregateUDF
Return the AggregateUDF
used by this AggregateFunctionExpr
Trait Implementations§
source§impl AggregateExpr for AggregateFunctionExpr
impl AggregateExpr for AggregateFunctionExpr
source§fn expressions(&self) -> Vec<Arc<dyn PhysicalExpr>>
fn expressions(&self) -> Vec<Arc<dyn PhysicalExpr>>
expressions that are passed to the Accumulator.
Single-column aggregations such as
sum
return a single value, others (e.g. cov
) return many.source§fn state_fields(&self) -> Result<Vec<Field>>
fn state_fields(&self) -> Result<Vec<Field>>
the fields that encapsulate the Accumulator’s state
the number of fields here equals the number of states that the accumulator contains
source§fn create_accumulator(&self) -> Result<Box<dyn Accumulator>>
fn create_accumulator(&self) -> Result<Box<dyn Accumulator>>
the accumulator used to accumulate values from the expressions.
the accumulator expects the same number of arguments as
expressions
and must
return states with the same description as state_fields
source§fn create_sliding_accumulator(&self) -> Result<Box<dyn Accumulator>>
fn create_sliding_accumulator(&self) -> Result<Box<dyn Accumulator>>
Creates accumulator implementation that supports retract
source§fn name(&self) -> &str
fn name(&self) -> &str
Human readable name such as
"MIN(c2)"
. The default
implementation returns placeholder text.source§fn order_bys(&self) -> Option<&[PhysicalSortExpr]>
fn order_bys(&self) -> Option<&[PhysicalSortExpr]>
Order by requirements for the aggregate function
By default it is
None
(there is no requirement)
Order-sensitive aggregators, such as FIRST_VALUE(x ORDER BY y)
should implement thissource§fn groups_accumulator_supported(&self) -> bool
fn groups_accumulator_supported(&self) -> bool
If the aggregate expression has a specialized
GroupsAccumulator
implementation. If this returns true,
[Self::create_groups_accumulator
] will be called.source§fn create_groups_accumulator(
&self
) -> Result<Box<dyn GroupsAccumulator, Global>, DataFusionError>
fn create_groups_accumulator( &self ) -> Result<Box<dyn GroupsAccumulator, Global>, DataFusionError>
Return a specialized
GroupsAccumulator
that manages state
for all groups. Read moresource§fn reverse_expr(&self) -> Option<Arc<dyn AggregateExpr, Global>>
fn reverse_expr(&self) -> Option<Arc<dyn AggregateExpr, Global>>
Construct an expression that calculates the aggregate in reverse.
Typically the “reverse” expression is itself (e.g. SUM, COUNT).
For aggregates that do not support calculation in reverse,
returns None (which is the default value).
source§impl Debug for AggregateFunctionExpr
impl Debug for AggregateFunctionExpr
Auto Trait Implementations§
impl !RefUnwindSafe for AggregateFunctionExpr
impl Send for AggregateFunctionExpr
impl Sync for AggregateFunctionExpr
impl Unpin for AggregateFunctionExpr
impl !UnwindSafe for AggregateFunctionExpr
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