Struct deltalake::datafusion::physical_expr::equivalence::OrderingEquivalenceClass

pub struct OrderingEquivalenceClass {
    pub orderings: Vec<Vec<PhysicalSortExpr>>,
}

An OrderingEquivalenceClass object keeps track of different alternative orderings than can describe a schema. For example, consider the following table:

|a|b|c|d|
|1|4|3|1|
|2|3|3|2|
|3|1|2|2|
|3|2|1|3|

Here, both vec![a ASC, b ASC] and vec![c DESC, d ASC] describe the table ordering. In this case, we say that these orderings are equivalent.

Fields

orderings: Vec<Vec<PhysicalSortExpr>>

Implementations

impl OrderingEquivalenceClass

pub fn empty() -> OrderingEquivalenceClass

Creates new empty ordering equivalence class.

pub fn clear(&mut self)

Clears (empties) this ordering equivalence class.

pub fn new(orderings: Vec<Vec<PhysicalSortExpr>>) -> OrderingEquivalenceClass

Creates new ordering equivalence class from the given orderings.

pub fn contains(&self, ordering: &Vec<PhysicalSortExpr>) -> bool

Checks whether ordering is a member of this equivalence class.

pub fn is_empty(&self) -> bool

Checks whether this ordering equivalence class is empty.

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

Returns an iterator over the equivalent orderings in this class.

pub fn len(&self) -> usize

Returns how many equivalent orderings there are in this class.

pub fn extend(&mut self, other: OrderingEquivalenceClass)

Extend this ordering equivalence class with the other class.

pub fn add_new_orderings( &mut self, orderings: impl IntoIterator<Item = Vec<PhysicalSortExpr>> )

Adds new orderings into this ordering equivalence class.

pub fn output_ordering(&self) -> Option<Vec<PhysicalSortExpr>>

Returns the concatenation of all the orderings. This enables merge operations to preserve all equivalent orderings simultaneously.

pub fn join_suffix( self, other: &OrderingEquivalenceClass ) -> OrderingEquivalenceClass

pub fn add_offset(&mut self, offset: usize)

Adds offset value to the index of each expression inside this ordering equivalence class.

pub fn get_options(&self, expr: &Arc<dyn PhysicalExpr>) -> Option<SortOptions>

Gets sort options associated with this expression if it is a leading ordering expression. Otherwise, returns None.

Trait Implementations

impl Clone for OrderingEquivalenceClass

fn clone(&self) -> OrderingEquivalenceClass

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for OrderingEquivalenceClass

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

Formats the value using the given formatter.

impl Hash for OrderingEquivalenceClass

fn hash<__H>(&self, state: &mut __H)

where __H: Hasher,

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl PartialEq for OrderingEquivalenceClass

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

This method tests for self and other values to be equal, and is used by ==.

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

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

impl Eq for OrderingEquivalenceClass

impl StructuralPartialEq for OrderingEquivalenceClass