Struct datafusion_physical_expr::equivalence::EquivalentClass

pub struct EquivalentClass<T = Column> { /* private fields */ }

EquivalentClass is a set of Columns or PhysicalSortExprs that are known to have the same value in all tuples in a relation. EquivalentClass<Column> is generated by equality predicates, typically equijoin conditions and equality conditions in filters. EquivalentClass<PhysicalSortExpr> is generated by the ROW_NUMBER window function.

Implementations

impl<T: Eq + Hash + Clone> EquivalentClass<T>

pub fn new(head: T, others: Vec<T>) -> EquivalentClass<T>

pub fn head(&self) -> &T

pub fn others(&self) -> &HashSet<T>

pub fn contains(&self, col: &T) -> bool

pub fn insert(&mut self, col: T) -> bool

pub fn remove(&mut self, col: &T) -> bool

pub fn iter(&self) -> impl Iterator<Item = &T>

pub fn len(&self) -> usize

pub fn is_empty(&self) -> bool

impl EquivalentClass<Vec<PhysicalSortExpr>>

pub fn add_offset(&self, offset: usize) -> Result<OrderingEquivalentClass>

Adds offset value to the index of each expression inside self.head and self.others.

pub fn normalize_with_equivalence_properties( &self, eq_properties: &EquivalenceProperties ) -> OrderingEquivalentClass

This function normalizes OrderingEquivalenceProperties according to eq_properties. More explicitly, it makes sure that expressions in oeq_class are head entries in eq_properties, replacing any non-head entries with head entries if necessary.

pub fn prefix_ordering_equivalent_class_with_existing_ordering( &self, existing_ordering: &[PhysicalSortExpr], eq_properties: &EquivalenceProperties ) -> OrderingEquivalentClass

Prefix with existing ordering.

Trait Implementations

impl<T: Clone> Clone for EquivalentClass<T>

fn clone(&self) -> EquivalentClass<T>

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<T: Debug> Debug for EquivalentClass<T>

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

Formats the value using the given formatter.