Module equivalence 

Structs

ConstExpr

A structure representing a expression known to be constant in a physical execution plan.

EquivalenceClass

An EquivalenceClass is a set of Arc<dyn PhysicalExpr>s that are known to have the same value for all tuples in a relation. These are generated by equality predicates (e.g. a = b), typically equi-join conditions and equality conditions in filters.

EquivalenceGroup

A collection of distinct EquivalenceClasses. This object supports fast lookups of expressions and their equivalence classes.

EquivalenceProperties

EquivalenceProperties stores information about the output of a plan node that can be used to optimize the plan. Currently, it keeps track of:

OrderingEquivalenceClass

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

ProjectionMapping

Stores the mapping between source expressions and target expressions for a projection.

Enums

AcrossPartitions

Represents whether a constant expression’s value is uniform or varies across partitions. Has two variants:

Functions

calculate_union

Calculates the union (in the sense of UnionExec) EquivalenceProperties of the given EquivalenceProperties in eqps according to the given output schema (which need not be the same with those of lhs and rhs as details such as nullability may be different).

convert_to_orderings

convert_to_sort_exprs

join_equivalence_properties

Calculate ordering equivalence properties for the given join operation.

project_ordering

Projects a single LexOrdering onto the given schema.

project_orderings

Projects a slice of LexOrderings onto the given schema.