Module datafusion_physical_expr::equivalence
source · Structs
- Equivalence Properties is a vec of EquivalentClass.
- EquivalentClass is a set of
Column
s orOrderedColumn
s 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<OrderedColumn>
is generated by theROW_NUMBER
window function. - This object represents a
Column
with a definite ordering.
Functions
- This function applies the given projection to the given equivalence properties to compute the resulting (projected) equivalence properties; e.g.
- This function applies the given projection to the given ordering equivalence properties to compute the resulting (projected) ordering equivalence properties; e.g.
Type Definitions
OrderingEquivalenceProperties
keeps track of columns that describe the global ordering of the schema. These columns are not necessarily same; e.g.