Package org.apache.druid.sql.calcite.rule

Class DruidCorrelateUnnestRule

java.lang.Object
org.apache.calcite.plan.RelOptRule
org.apache.druid.sql.calcite.rule.DruidCorrelateUnnestRule
public class DruidCorrelateUnnestRule extends org.apache.calcite.plan.RelOptRule
This class creates the rule to abide by for creating correlations during unnest. Typically, Calcite plans the unnest query such as SELECT * from numFoo, unnest(dim3) in the following way: 
 80:LogicalCorrelate(correlation=[$cor0], joinType=[inner], requiredColumns=[{3}])
   6:LogicalTableScan(subset=[rel#74:Subset#0.NONE.[]], table=[[druid, numfoo]])
   78:Uncollect(subset=[rel#79:Subset#3.NONE.[]])
     76:LogicalProject(subset=[rel#77:Subset#2.NONE.[]], EXPR$0=[MV_TO_ARRAY($cor0.dim3)])
       7:LogicalValues(subset=[rel#75:Subset#1.NONE.[0]], tuples=[[{ 0 }]])

DruidUnnestRule takes care of the Uncollect(last 3 lines) to generate a DruidUnnestRel thereby reducing the logical plan to: 

        LogicalCorrelate
           /       \
      DruidRel    DruidUnnestDataSourceRel
This forms the premise of this rule. The goal is to transform the above-mentioned structure in the tree with a new rel DruidCorrelateUnnestRel which shall be created here.

  • 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
    DruidCorrelateUnnestRule(PlannerContext plannerContext)
     

  • Method Summary

    Modifier and Type
    Method
    Description
    boolean
    matches(org.apache.calcite.plan.RelOptRuleCall call)
     
    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, 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

  • Constructor Details

    • DruidCorrelateUnnestRule

      public DruidCorrelateUnnestRule(PlannerContext plannerContext)

  • Method Details

    • matches

      public boolean matches(org.apache.calcite.plan.RelOptRuleCall call)
      Overrides:
      matches in class org.apache.calcite.plan.RelOptRule

    • onMatch

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