Struct StatisticsContext 

pub struct StatisticsContext { /* private fields */ }

Owns the bottom-up traversal and per-walk memoization cache for statistics computation. Call StatisticsContext::compute to walk a plan tree.

Implementations

impl StatisticsContext

pub fn new() -> Self

Creates a context with an empty cache.

pub fn reset_cache(&self)

Clears the memoization cache.

The cache is keyed by raw plan-node pointers, which are only stable while the current plan tree is alive. Reset between optimizer passes (which rewrite the plan) when reusing one context across them, so stale pointer keys cannot collide.

pub fn compute( &self, plan: &dyn ExecutionPlan, args: &StatisticsArgs, ) -> Result<Arc<Statistics>>

Computes statistics for plan, resolving children first and passing the results to ExecutionPlan::statistics_from_inputs.

When args.partition() is Some(idx), idx is validated against the plan’s partition count.

Trait Implementations

impl Default for StatisticsContext

fn default() -> Self

Returns the “default value” for a type.