Struct ColumnCorrelations 

pub struct ColumnCorrelations { /* private fields */ }

Tracks correlations between columns within a table

Implementations

impl ColumnCorrelations

pub fn new() -> Self

Create empty correlation tracker

pub fn add_correlation( &mut self, col1: &str, col2: &str, coefficient: CorrelationCoefficient, )

Add a correlation between two columns

pub fn add_functional_dep(&mut self, determinant: &str, dependent: &str)

Add a functional dependency: determinant -> dependent e.g., add_functional_dep(“zip_code”, “city”)

pub fn get_correlation(&self, col1: &str, col2: &str) -> CorrelationCoefficient

Get correlation between two columns (0.0 if unknown)

pub fn determines(&self, col1: &str, col2: &str) -> bool

Check if col1 functionally determines col2

pub fn correlated_columns( &self, col: &str, ) -> Vec<(&str, CorrelationCoefficient)>

Get all columns correlated with the given column

pub fn combined_selectivity(&self, selectivities: &[(&str, f64)]) -> f64

Compute combined selectivity for multiple predicates considering correlations

This is the KEY method that makes correlation tracking useful.

Arguments

• selectivities - List of (column_name, selectivity) pairs

Returns

Combined selectivity accounting for correlations

pub fn detect_correlations_from_sample( col1_values: &[Value], col2_values: &[Value], ) -> Option<CorrelationCoefficient>

Detect correlations from sample data

This uses Pearson correlation coefficient for numeric columns and Cramér’s V for categorical columns.

Trait Implementations

impl Clone for ColumnCorrelations

fn clone(&self) -> ColumnCorrelations

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for ColumnCorrelations

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

Formats the value using the given formatter.

impl Default for ColumnCorrelations

fn default() -> ColumnCorrelations

Returns the “default value” for a type.