Struct CardinalityFeedback 

pub struct CardinalityFeedback { /* private fields */ }

Feedback from runtime execution about actual cardinalities.

This struct collects actual row counts at various points during query execution, allowing comparison with optimizer estimates.

Implementations

impl CardinalityFeedback

pub fn new() -> Self

Creates a new empty feedback collector.

pub fn record(&mut self, operator_id: &str, count: u64)

Records the final actual cardinality for an operator.

pub fn add_rows(&self, operator_id: &str, count: u64)

Adds to the running count for an operator (thread-safe).

pub fn init_counter(&mut self, operator_id: &str)

Initializes a running counter for an operator.

pub fn finalize_counter(&mut self, operator_id: &str)

Finalizes the running count into the actuals.

pub fn get(&self, operator_id: &str) -> Option<u64>

Gets the actual count for an operator.

pub fn get_running(&self, operator_id: &str) -> Option<u64>

Gets the current running count for an operator.

pub fn all_actuals(&self) -> &HashMap<String, u64>

Returns all recorded actuals.

Trait Implementations

impl Debug for CardinalityFeedback

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

Formats the value using the given formatter.

impl Default for CardinalityFeedback

fn default() -> CardinalityFeedback

Returns the “default value” for a type.