PredicateHelper Scala Trait¶

PredicateHelper defines the <> that are used to work with predicates (mainly).

[[methods]] .PredicateHelper's Methods [cols="1,2",options="header",width="100%"] |=== | Method | Description

=== [[splitConjunctivePredicates]] Splitting Conjunctive Predicates -- splitConjunctivePredicates Method

[source, scala]¶

splitConjunctivePredicates(condition: Expression): Seq[Expression]¶

splitConjunctivePredicates takes the input condition expressions/Expression.md[expression] and splits it to two expressions if they are children of a And binary expression.

splitConjunctivePredicates splits the child expressions recursively down the child expressions until no conjunctive And binary expressions exist.

=== [[splitDisjunctivePredicates]] splitDisjunctivePredicates Method

[source, scala]¶

splitDisjunctivePredicates(condition: Expression): Seq[Expression]¶

splitDisjunctivePredicates...FIXME

NOTE: splitDisjunctivePredicates is used when...FIXME

=== [[replaceAlias]] replaceAlias Method

[source, scala]¶

replaceAlias( condition: Expression, aliases: AttributeMap[Expression]): Expression

replaceAlias...FIXME

NOTE: replaceAlias is used when...FIXME

=== [[canEvaluate]] canEvaluate Method

[source, scala]¶

canEvaluate(expr: Expression, plan: LogicalPlan): Boolean¶

canEvaluate...FIXME

NOTE: canEvaluate is used when...FIXME

=== [[canEvaluateWithinJoin]] canEvaluateWithinJoin Method

[source, scala]¶

canEvaluateWithinJoin(expr: Expression): Boolean¶

canEvaluateWithinJoin indicates whether a expressions/Expression.md[Catalyst expression] can be evaluated within a join, i.e. when one of the following conditions holds:

• Expression is expressions/Expression.md#deterministic[deterministic]

• Expression is not Unevaluable, ListQuery or Exists

• Expression is a SubqueryExpression with no child expressions

• Expression is a AttributeReference

• Any expression with child expressions that meet one of the above conditions

[NOTE]¶

canEvaluateWithinJoin is used when:

• PushPredicateThroughJoin logical optimization rule is PushPredicateThroughJoin.md#apply[executed]

* ReorderJoin logical optimization rule does ReorderJoin.md#createOrderedJoin[createOrderedJoin]¶