Package io.trino.sql.planner.iterative.rule

Class UnwrapCastInComparison

java.lang.Object

io.trino.sql.planner.iterative.rule.ExpressionRewriteRuleSet

io.trino.sql.planner.iterative.rule.UnwrapCastInComparison

public class UnwrapCastInComparison
extends ExpressionRewriteRuleSet

Given s of type S, a constant expression t of type T, and when an implicit cast exists between S->T, converts expression of the form:

 CAST(s as T) = t
 

into

 s = CAST(t as S)
 

For example:

 CAST(x AS bigint) = bigint '1'
 

turns into

 x = smallint '1'
 

It can simplify expressions that are known to be true or false, and remove the comparisons altogether. For example, give x::smallint, for an expression like:

 CAST(x AS bigint) > bigint '10000000'
 

Nested Class Summary

Nested classes/interfaces inherited from class io.trino.sql.planner.iterative.rule.ExpressionRewriteRuleSet

ExpressionRewriteRuleSet.ExpressionRewriter

Constructor Summary

Constructors

Constructor	Description
UnwrapCastInComparison(PlannerContext plannerContext, IrTypeAnalyzer typeAnalyzer)

Method Summary

Modifier and Type	Method	Description
static Expression	falseIfNotNull(Expression argument)
static Expression	trueIfNotNull(Expression argument)
static Expression	unwrapCasts(Session session, PlannerContext plannerContext, IrTypeAnalyzer typeAnalyzer, TypeProvider types, Expression expression)

Methods inherited from class io.trino.sql.planner.iterative.rule.ExpressionRewriteRuleSet

aggregationExpressionRewrite, filterExpressionRewrite, joinExpressionRewrite, patternRecognitionExpressionRewrite, projectExpressionRewrite, rules, valuesExpressionRewrite

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

UnwrapCastInComparison

public UnwrapCastInComparison(PlannerContext plannerContext,
 IrTypeAnalyzer typeAnalyzer)

Method Details

unwrapCasts

public static Expression unwrapCasts(Session session,
 PlannerContext plannerContext,
 IrTypeAnalyzer typeAnalyzer,
 TypeProvider types,
 Expression expression)

falseIfNotNull

public static Expression falseIfNotNull(Expression argument)

trueIfNotNull

public static Expression trueIfNotNull(Expression argument)