Class CaseToCoalesceRule

java.lang.Object
org.apache.calcite.plan.RelOptRule
org.apache.druid.sql.calcite.rule.CaseToCoalesceRule
All Implemented Interfaces:
org.apache.calcite.rel.rules.SubstitutionRule, org.apache.calcite.rel.rules.TransformationRule

public class CaseToCoalesceRule extends org.apache.calcite.plan.RelOptRule implements org.apache.calcite.rel.rules.SubstitutionRule
Rule that un-does the rewrite from SqlCoalesceFunction.rewriteCall(org.apache.calcite.sql.validate.SqlValidator, org.apache.calcite.sql.SqlCall). Important because otherwise COALESCE turns into a gnarly CASE with duplicated expressions. We must un-do the rewrite rather than disable SqlValidator.Config.callRewrite(), because we rely on validator rewrites in other cases, such as EarliestLatestAnySqlAggregator.EARLIEST and EarliestLatestAnySqlAggregator.LATEST.
  • Nested Class Summary

    Nested classes/interfaces inherited from class org.apache.calcite.plan.RelOptRule

    org.apache.calcite.plan.RelOptRule.ConverterRelOptRuleOperand
  • Field Summary

    Fields inherited from class org.apache.calcite.plan.RelOptRule

    description, operands, relBuilderFactory
  • Constructor Summary

    Constructors
    Constructor
    Description
     
  • Method Summary

    Modifier and Type
    Method
    Description
    void
    onMatch(org.apache.calcite.plan.RelOptRuleCall call)
     

    Methods inherited from class org.apache.calcite.plan.RelOptRule

    any, convert, convert, convert, convert, convertList, convertOperand, convertOperand, equals, equals, getOperand, getOperands, getOutConvention, getOutTrait, hashCode, matches, none, operand, operand, operand, operand, operand, operandJ, operandJ, some, toString, unordered

    Methods inherited from class java.lang.Object

    clone, finalize, getClass, notify, notifyAll, wait, wait, wait

    Methods inherited from interface org.apache.calcite.rel.rules.SubstitutionRule

    autoPruneOld
  • Constructor Details

    • CaseToCoalesceRule

      public CaseToCoalesceRule()
  • Method Details

    • onMatch

      public void onMatch(org.apache.calcite.plan.RelOptRuleCall call)
      Specified by:
      onMatch in class org.apache.calcite.plan.RelOptRule