Enum WcojVarOrderingKind 

pub enum WcojVarOrderingKind {
    Disabled,
    LeaderCardinality,
    HeatAware,
}

Selector for the WCOJ variable-ordering cost model.

Disabled is the load-bearing default: when set, the promoter never emits RirNode::MultiWayJoin::var_order, preserving existing triangle, 4-cycle, recursive, and selectivity-aware dispatch row-set semantics.

Variants

Disabled

Variable-ordering disabled: promoter never sets var_order.

LeaderCardinality

Use the default LeaderCardinalityModel to pick a stats-driven leader for triangle / 4-cycle WCOJ inputs.

HeatAware

Use HeatAwareLeaderModel: combines cardinality, access heat, and observed join selectivity into a composite score. Hot relations and relations in tight (low selectivity) edges get demoted from the leader slot; cold extensional rels are preferred as leader. Same threshold gate as LeaderCardinality via effective_wcoj_var_ordering_threshold().

Trait Implementations

impl Clone for WcojVarOrderingKind

fn clone(&self) -> WcojVarOrderingKind

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for WcojVarOrderingKind

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

Formats the value using the given formatter.

impl PartialEq for WcojVarOrderingKind

fn eq(&self, other: &WcojVarOrderingKind) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Copy for WcojVarOrderingKind

impl Eq for WcojVarOrderingKind

impl StructuralPartialEq for WcojVarOrderingKind