Struct AdaptiveContext 

pub struct AdaptiveContext { /* private fields */ }

Context for adaptive query execution.

Holds both estimated and actual cardinalities, and provides methods to determine when re-optimization should occur.

Implementations

impl AdaptiveContext

pub fn new() -> Self

Creates a new adaptive context with default settings.

pub fn with_thresholds(threshold: f64, min_rows: u64) -> Self

Creates a context with custom thresholds.

pub fn set_estimate(&mut self, operator_id: &str, estimate: f64)

Sets the estimated cardinality for an operator.

pub fn record_actual(&mut self, operator_id: &str, actual: u64)

Records the actual cardinality for an operator.

pub fn apply_feedback(&mut self, feedback: &CardinalityFeedback)

Applies feedback from a CardinalityFeedback collector.

pub fn has_significant_deviation(&self) -> bool

Checks if any checkpoint shows significant deviation.

pub fn should_reoptimize(&mut self) -> bool

Determines if re-optimization should be triggered.

Returns true if:

• There’s significant deviation from estimates
• We’ve processed enough rows to make a meaningful decision
• Re-optimization hasn’t already been triggered

pub fn trigger_operator(&self) -> Option<&str>

Returns the operator that triggered re-optimization, if any.

pub fn get_checkpoint( &self, operator_id: &str, ) -> Option<&CardinalityCheckpoint>

Gets the checkpoint for an operator.

pub fn all_checkpoints(&self) -> &HashMap<String, CardinalityCheckpoint>

Returns all checkpoints.

pub fn correction_factor(&self, operator_id: &str) -> f64

Calculates a correction factor for a specific operator.

This factor can be used to adjust remaining cardinality estimates.

pub fn summary(&self) -> AdaptiveSummary

Returns summary statistics about the adaptive execution.

pub fn reset(&mut self)

Resets the context for a new execution.

Trait Implementations

impl Debug for AdaptiveContext

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

Formats the value using the given formatter.

impl Default for AdaptiveContext

fn default() -> Self

Returns the “default value” for a type.