Struct StatisticsRegistry 

pub struct StatisticsRegistry { /* private fields */ }

Registry that chains StatisticsProvider implementations.

The registry is a stateless provider chain: it holds no mutable state and is cheaply Cloneable / Send / Sync.

Implementations

impl StatisticsRegistry

pub fn new() -> StatisticsRegistry

Create a new empty registry.

With no providers, compute() falls back to each plan node’s built-in partition_statistics(). Register providers to enhance statistics (e.g., inject NDV, use histograms).

pub fn with_providers( providers: Vec<Arc<dyn StatisticsProvider>>, ) -> StatisticsRegistry

Create a registry with the given provider chain.

pub fn default_with_builtin_providers() -> StatisticsRegistry

Create a registry pre-loaded with the standard built-in providers.

Provider order (first match wins):

1. FilterStatisticsProvider
2. ProjectionStatisticsProvider
3. PassthroughStatisticsProvider
4. AggregateStatisticsProvider
5. JoinStatisticsProvider
6. LimitStatisticsProvider
7. UnionStatisticsProvider
8. DefaultStatisticsProvider

pub fn register(&mut self, provider: Arc<dyn StatisticsProvider>)

Register a provider at the front of the chain (higher priority).

pub fn providers(&self) -> &[Arc<dyn StatisticsProvider>]

Returns the current provider chain.

pub fn compute( &self, plan: &(dyn ExecutionPlan + 'static), ) -> Result<ExtendedStatistics, DataFusionError>

Compute extended statistics for a plan through the provider chain.

Performs a bottom-up tree walk: child statistics are computed recursively and passed to providers, mirroring how partition_statistics composes operators. Once #20184 lands, the registry can feed enriched base stats directly into partition_statistics(child_stats), removing the need for a separate walk.

If no providers are registered, falls back to the plan’s built-in partition_statistics(None) with no overhead.

pub fn compute_base( &self, plan: &(dyn ExecutionPlan + 'static), ) -> Result<Statistics, DataFusionError>

Compute statistics and return only the base Statistics (no extensions).

Convenience method for callers that don’t need extensions.

Trait Implementations

impl Clone for StatisticsRegistry

fn clone(&self) -> StatisticsRegistry

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for StatisticsRegistry

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

Formats the value using the given formatter.

impl Default for StatisticsRegistry

fn default() -> StatisticsRegistry

Returns the “default value” for a type.