Struct OptimizeAggregateOrder

pub struct OptimizeAggregateOrder {}

This optimizer rule checks ordering requirements of aggregate expressions.

There are 3 kinds of aggregators in terms of ordering requirements:

• AggregateOrderSensitivity::Insensitive, meaning that ordering is not important.
• AggregateOrderSensitivity::HardRequirement, meaning that the aggregator requires a specific ordering.
• AggregateOrderSensitivity::Beneficial, meaning that the aggregator can handle unordered input, but can run more efficiently if its input conforms to a specific ordering.

This rule analyzes aggregate expressions of type Beneficial to see whether their input ordering requirements are satisfied. If this is the case, the aggregators are modified to run in a more efficient mode.

Implementations

impl OptimizeAggregateOrder

pub fn new() -> Self

Trait Implementations

impl Debug for OptimizeAggregateOrder

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

Formats the value using the given formatter.

impl Default for OptimizeAggregateOrder

fn default() -> OptimizeAggregateOrder

Returns the “default value” for a type.

impl PhysicalOptimizerRule for OptimizeAggregateOrder

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

Applies the OptimizeAggregateOrder rule to the provided execution plan.

This function traverses the execution plan tree, identifies AggregateExec nodes, and optimizes their aggregate expressions based on existing input orderings. If optimizations are applied, it returns a modified execution plan.

Arguments

• plan - The root of the execution plan to optimize.
• _config - Configuration options (currently unused).

Returns

A Result containing the potentially optimized execution plan or an error.

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.