Struct SkewJoinRule 

pub struct SkewJoinRule { /* private fields */ }

AQE rule that splits hot partitions of a HashJoin’s probe side using salting, and replicates the build side accordingly.

Supports both static salting (fixed factor) and adaptive salting where the factor scales with the severity of the skew — more skewed partitions get more sub-partitions. The adaptive mode uses: factor = min(max_factor, ceil(rows / (threshold * median))).

Implementations

impl SkewJoinRule

pub fn new(threshold: f64, factor: u32) -> Self

Create a rule that flags partitions exceeding threshold × median.

pub fn with_default_factor(threshold: f64) -> Self

Like new but with the DEFAULT_SALT_FACTOR.

pub fn with_adaptive_salty(self, max_factor: u32) -> Self

Enable adaptive salting: the factor scales with skew severity up to max_factor. When max_factor is 0, static salting is used.

pub fn detect_hot_partitions(&self, stats: &[RuntimeStats]) -> Vec<usize>

Detect hot partitions from runtime stats.

Trait Implementations

impl AqeRule for SkewJoinRule

fn name(&self) -> &str

Short, stable rule name used in explain and diagnostics output.

fn apply( &self, plan: &PhysicalPlan, stats: &[RuntimeStats], ) -> Option<PhysicalPlan>

Apply the AQE rule given collected RuntimeStats for each stage.