Struct JoinRelation 

pub struct JoinRelation { /* private fields */ }

One relation participating in a join, with its per-attribute degrees.

Implementations

impl JoinRelation

pub fn new(rows: u64) -> Self

A relation of rows rows with no degree information. Every attribute defaults to AttributeDegree::unknown.

Examples

use samkhya_core::degree::JoinRelation;

assert_eq!(JoinRelation::new(42).rows(), 42);

pub fn with_degree( self, attribute: AttributeId, degree: AttributeDegree, ) -> Self

Attach a degree bound for one join attribute.

Examples

use samkhya_core::degree::{AttributeDegree, JoinRelation};

let r = JoinRelation::new(100)
    .with_degree(7, AttributeDegree::from_distinct(100, 100));
assert_eq!(r.degree(7).max_degree(), 1);

pub const fn rows(&self) -> u64

Row count of this relation.

pub fn degree(&self, attribute: AttributeId) -> AttributeDegree

Degree bound for attribute, defaulting to the always-sound AttributeDegree::unknown when none was supplied.

Examples

use samkhya_core::degree::JoinRelation;

// No degree registered → falls back to the row count.
assert_eq!(JoinRelation::new(64).degree(3).max_degree(), 64);

Trait Implementations

impl Clone for JoinRelation

fn clone(&self) -> JoinRelation

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for JoinRelation

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

Formats the value using the given formatter.