Struct datafusion::physical_optimizer::topk_aggregation::TopKAggregation

pub struct TopKAggregation {}

An optimizer rule that passes a limit hint to aggregations if the whole result is not needed

Implementations

impl TopKAggregation

pub fn new() -> Self

Create a new LimitAggregation

Trait Implementations

impl Default for TopKAggregation

fn default() -> Self

Returns the “default value” for a type.

impl PhysicalOptimizerRule for TopKAggregation

fn optimize( &self, plan: Arc<dyn ExecutionPlan>, config: &ConfigOptions ) -> Result<Arc<dyn ExecutionPlan>>

Rewrite plan to an optimized form

fn name(&self) -> &str

A human readable name for this optimizer rule

fn schema_check(&self) -> bool

A flag to indicate whether the physical planner should valid the rule will not change the schema of the plan after the rewriting. Some of the optimization rules might change the nullable properties of the schema and should disable the schema check.