Struct Statistics 

pub struct Statistics { /* private fields */ }

Statistics manager for query optimization

Implementations

impl Statistics

pub fn new() -> Self

Create a new statistics manager

pub fn update_table_stats(&self, table_name: String, stats: TableStats)

Update table statistics

pub fn get_table_stats(&self, table_name: &str) -> Option<TableStats>

Get table statistics

pub fn update_column_stats(&self, column_key: String, stats: ColumnStats)

Update column statistics

pub fn get_column_stats(&self, column_key: &str) -> Option<ColumnStats>

Get column statistics

pub fn is_empty(&self) -> bool

Check if statistics are empty

pub fn clear(&self)

Clear all statistics

pub fn estimate_join_selectivity( &self, left_table: &str, right_table: &str, join_column: &str, ) -> f64

Estimate join selectivity

pub fn estimate_filter_selectivity( &self, column_key: &str, operator: &str, ) -> f64

Estimate filter selectivity

Trait Implementations

impl Default for Statistics

fn default() -> Self

Returns the “default value” for a type.